United Ireland & the Border Poll
Tracking polling on Irish reunification and Northern Ireland's constitutional status — the border-poll threshold, and the changing demography of the North. Data from Red C, Ireland Thinks, Ipsos B&A and NISRA.
Under the Good Friday Agreement, the UK Secretary of State for Northern Ireland must call a border poll once it appears likely that a majority in the North would vote for Irish unity — this Northern Ireland figure, not any Republic-only or island-wide number, is the one that actually triggers that mechanism. Support has risen 9.13 points since 1998, peaking at 46.00% in 2019; the current weighted average is 11.87 points off that high. The headline figure above is a recency-, sample-size- and pollster-trust-weighted average (200-day half-life) with pollster house effects corrected for, not the single latest poll — random- probability academic surveys (e.g. NI Life & Times, ARINS) carry more weight than opt-in online-panel trackers at the same recency and sample size, reflecting their methodological rigor. See the full methodology below. See the Republic of Ireland figures below, and the blended island-wide picture further down the page.
Northern Ireland border poll: full history
Every poll since 1998, with the same weighted-average line as above — support has narrowed from 38.00 points behind in 1998 to 12.85 points behind today, peaking at 46.00% in 2019.
Net unity support in Northern Ireland (Unity − Stay)
The gap between the two options above, as a single line — positive means unity is ahead, negative means staying in the UK is ahead. Same weighted-average methodology as the chart above, applied to the full sample.
Shaded area = distance from parity at each point (dot size ∝ sample size). Closest reading to a 50/50 split was 1.00 points apart, in 2019 (Lord Ashcroft Polls).
Support for unity in the Republic has risen 6.48 points since 2010, peaking at 66.00% in 2022; the latest reading (Nov 2023) is 2.00 points off that high. Among voters who have made up their minds, a clear majority (78.35%) already back a united Ireland. Under the Good Friday Agreement, the UK Secretary of State for Northern Ireland must call a border poll once it appears likely that a majority in the North would vote for unity — see the composite sentiment index above for the island-wide picture.
Direct-support polls have held well above 50% since 2010
Every standalone survey asking Republic of Ireland voters a direct unity question since 2010 has found majority support — support peaked at 66.00% in 2022 (ARINS / The Irish Times) and stood at 64.00% in the most recent Nov 2023 poll. The dashed line marks the 50% threshold. The line shows a recency- and sample-size-weighted moving average with shaded 95% margin-of-error bands, not a straight connect-the-dots through every reading.
Not all "united Ireland" polls ask the same question
The chart above tracks pollsters who ask a direct, border-poll-style question — broadly, "if a poll were held tomorrow, how would you vote?" A second group of surveys, including RTÉ's long-running Claire Byrne Live/Amárach series, ask a more aspirational question about wanting to see a united Ireland at some point, rather than voting in an actual poll tomorrow — and consistently register 10–20 points higher as a result.
Question wording can move the topline dramatically even within one survey: when the polling firm EMI added the phrase "in the EU" to the standard united Ireland question, support in Northern Ireland jumped to 63% — far above what "many other surveys" find — which EMI's own CEO attributed directly to that framing. Pollster name alone doesn't tell you what was actually asked, so we keep these differently-worded series visually separate below rather than merging them into one misleading trend line.
The aspirational-framing series
RTÉ's Claire Byrne Live/Amárach series and the newest Amárach/ European Movement Ireland poll ask about wanting unity in general, not voting in a poll tomorrow — hence the much higher numbers. The line is a recency-, sample-size- and pollster-trust-weighted average with pollster house effects corrected for (the same method used above), not a straight connect-the-dots between just 7 polls spread over 11 years — the shaded band is its 95% margin of error.
Brexit reshaped the debate in the North
Northern Ireland voted to remain in the EU in 2016. Years on, opinion has hardened against Brexit — a key driver of the shift toward unity.
The North is changing: 2021 Census
For the first time since partition in 1921, more people in Northern Ireland come from a Catholic than a Protestant background.
Catholic-background residents (45.7%) now outnumber those from a Protestant background (43.5%) — a historic reversal from 1921, when Protestants made up roughly two-thirds of the population.
Irish and Northern Irish identities together now rival British identity, and a large "neither / both" middle increasingly holds the balance in any future border poll.
This index combines every poll on this page — Northern Ireland border polls (the actual mechanism specified in the Good Friday Agreement), Republic of Ireland direct-support polls, and the Republic's more aspirational "would you like to see unity" series — from the first post-Agreement poll in 1998 to today. Each of the three builds its own recency-, sample-size- and pollster-trust- weighted trend (the same method as the charts above, not a straight line between polls); the index shown here is the equal-weighted average of those three trends at every year, so it always blends all three jurisdictions/wordings rather than whichever one happened to be polled in a given year. The shaded band is a genuine margin of error that narrows with more, larger or higher-trust polls in a period and widens with fewer or lower-trust ones — not a fixed width. Dots mark years with at least one real poll; individual polls, split out by jurisdiction and question wording, are charted separately below. Individual poll figures — unity/stay/unsure or yes/no/undecided — often don't add to exactly 100%: most surveys also offer options like "other," "would not vote" or "refused" that this page doesn't chart separately, so a small residual is expected and isn't a data error.
The Case for a United Ireland
Arguments advanced by advocates of reunification.
Back inside the EU
Reunification would bring Northern Ireland back fully into the European Union and its single market — reversing Brexit for the North and restoring EU citizenship, funding and freedom of movement for everyone on the island.
A single all-island economy
Economic modelling (ESRI, and international studies) points to significant long-run gains from removing the border, harmonising regulation and building one integrated market of roughly 7 million people.
Integrated healthcare
All-island health services — from cross-border cancer care to a single children's heart-surgery network — already show how shared provision can cut waiting times and duplication across the island.
Ending partition
A united Ireland would resolve a century-old constitutional question peacefully and democratically, through the concurrent referendums set out in the Good Friday Agreement.
Demographic momentum
The 2021 census recorded a Catholic-background plurality in Northern Ireland for the first time, and a growing "neither" middle — reshaping the long-term arithmetic of a border poll.
Rights & identity for all
The Good Friday framework guarantees that British, Irish and Northern Irish identities — and both traditions — would be protected and cherished in a new, shared Ireland.
The Case for the Union
Arguments advanced by unionists and supporters of Northern Ireland's current constitutional status.
The principle of consent
The Good Friday Agreement guarantees Northern Ireland's constitutional status can only change with the consent of a majority of its people, voting in a referendum — the same principle that protects the aspiration to unity if opinion ever shifts that way.
British identity within the Union
A large share of Northern Ireland's population identifies as British (31.9% "British" in the 2021 census) and sees continued UK membership, not just practical considerations, as core to that identity.
Cost and pace of transition
Independent studies put the fiscal cost of replacing the UK subvention and harmonising pay, pensions and public services at roughly €3bn in year one (DCU/Ulster University, 2025), with estimates of the ongoing subvention itself ranging from £1.5bn to the £10bn+ figure more commonly cited — the range itself is a live part of the debate.
Currency & economic integration
Northern Ireland's economy, currency (sterling) and public institutions — the NHS, benefits system, pensions — are fully integrated with the rest of the UK; unpicking and re-integrating them with the Republic's systems would be a major practical undertaking either way.
No settled majority for change
Despite a Catholic-background plurality since the 2021 census, polling on this site's own trend charts has not shown a consistent pro-unity majority in Northern Ireland — academic research (the ARINS/Liverpool study) finds the pro-unity vote share has not grown in step with the Catholic-background population share since 1998.
Post-conflict stability
Some unionists and observers argue that pursuing a border poll without durable cross-community consensus risks unsettling the peace built since the 1998 Agreement, rather than delivering the reconciliation both traditions say they want.
Building a Shared Future
A united Ireland envisioned in the Good Friday Agreement is a shared home for both traditions. Cross-community reconciliation — from sport to schools — is already laying the groundwork for a peaceful, agreed future.
PeacePlayers
Brings together young people from Catholic and Protestant communities in Belfast — and in divided societies worldwide — through basketball. "Children who play together can learn to live together."
Corrymeela
Northern Ireland's oldest peace and reconciliation community, hosting cross-community dialogue and residentials at Ballycastle since 1965.
Co-operation Ireland
Builds cross-border and cross-community relationships North and South, working with both traditions and both governments.
Integrated education
A growing movement of schools educating Catholic and Protestant children side by side — consistently over-subscribed and backed by the Integrated Education Fund.
Glencree Centre
A County Wicklow centre for peace and reconciliation facilitating dialogue between communities on the island and beyond since 1974.
Shared Island Unit
An Irish Government initiative investing in all-island infrastructure, research and civic dialogue to deepen understanding across the island.
How Catholics became the largest community background in the North
The 2021 census was the first in Northern Ireland's history to record more people from a Catholic than a Protestant community background — but it was the culmination of a two-decade trend, not a one-off jump. NISRA's "religion or religion brought up in" question — the measure that actually decides this, since it re-assigns people with no current religion to the community they were raised in — has been asked on a comparable basis since 2001.
Read these estimates carefully. Both the 2031 figure and the 50%-crossing year are a straight line fitted through just three census points (2001, 2011, 2021) — the census only runs once a decade, so there's no way to check either more often than that. The rate of increase has already slowed between the two most recent censuses (+1.3pts in the 2000s vs +0.6pts in the 2010s), which a straight line can't capture — these are illustrative extrapolations of the historical trend, not demographic forecasts.
Demographic share has not translated into vote share. The Institute of Irish Studies (University of Liverpool) — whose surveys feed several of the NI poll figures on this page — put it bluntly in its December 2025 report: "the pro-unity vote has failed to grow post-1998 despite demographic change," even though "there has been a notable plurality of electoral entrants" from a Catholic background "for nearly 3 decades." Its own modelling concludes there will be no majority group by community background in Northern Ireland in either the short or medium term, as birth-rate decline now affects both traditions and growth is concentrated among those of no or other faith — a group that splits toward staying in the UK, not toward unity.
How border-poll voting intention splits by community background
15.4% of Catholic-background respondents would vote to stay in the UK, and 9.1% of Protestant-background respondents would vote for unity — real crossover in both directions, which is why rising Catholic-background population share and rising unity vote share are related but not the same number. Source: Institute of Irish Studies (Univ. of Liverpool) / Social Market Research, December 2025.
Do people in Northern Ireland want the referendums held at all?
A different, prior question from how anyone would actually vote: whether people even want concurrent referendums put to the North and South. ARINS/Irish Times has tracked this since 2022.
Support for holding the referendums has risen from 55% in 2022 to 63% in 2024 — a majority now favour asking the question, which is a separate finding from how that vote would actually go. Source: ARINS/Irish Times North & South Research 2024.
Would people accept the outcome they didn't vote for?
ARINS/Irish Times asked Northern Ireland respondents how they'd react if a concurrent referendum went the way they didn't want — not just what they'd vote, but whether they could live with losing. Both communities report far more willingness to accept the "losing" result than adversarial political rhetoric usually implies.
95% of Catholic-background respondents would happily accept or could live with NI staying in the UK; 77% of Protestant-background respondents would happily accept or could live with a united Ireland (dark = "would happily accept," light = "not happy but could live with it," red = "would find it almost impossible to accept"). Source: ARINS/Irish Times North & South Research 2024 (Ipsos NI, fieldwork Aug-Sep 2024, n=1,000).
What actually triggers a border poll
The Good Friday Agreement (1998) is a political agreement; the mechanism that gives it legal force in UK law is Schedule 1 of the Northern Ireland Act 1998. Three provisions matter:
"The Secretary of State may by order direct the holding of a poll for the purposes of section 1 on a date specified in the order." — the Secretary of State can call a poll at any time, at their own discretion, even without the trigger below being met.
"The Secretary of State shall exercise the power under paragraph 1 if at any time it appears likely to him that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland." — this is the actual legal trigger: not a fixed poll number, but the Secretary of State's own judgement that a "Yes" majority now looks likely.
"The Secretary of State shall not make an order under paragraph 1 earlier than seven years after the holding of a previous poll under this Schedule." — once a border poll is held (whatever the result), the next one can't be called for at least seven years.
If a poll were called and passed, a concurrent referendum would also be held in the Republic of Ireland (under its own constitutional amendment process) — unity requires simple majorities in both jurisdictions. Source: Northern Ireland Act 1998, Schedule 1, as published on legislation.gov.uk.
Republic of Ireland — Full Polling History
Every figure below is attributed to a named pollster; follow the link for the source.
Background & Context
Standalone surveys asking Republic of Ireland voters a direct unity question have found majority support in every reading since 2010, currently standing at 64.00% in the Nov 2023 ARINS / The Irish Times poll. In Northern Ireland, support has risen from 25.00% shortly after the 1998 Agreement to 33.20% today — the 2016 Brexit referendum, which imposed a hard economic border question on the island, is widely credited with accelerating that shift.
Under the Good Friday Agreement (1998), the British Secretary of State for Northern Ireland must call a border poll once it appears likely that a majority would vote for a united Ireland. Concurrent referendums would then be held North and South, with a simple majority in each deciding the outcome.
The 2021 census marked a demographic turning point, recording a Catholic-background plurality in the North for the first time. Combined with a growing "neither unionist nor nationalist" middle and record polling for unity in the South, the constitutional question is now firmly on the political agenda through initiatives like the government's Shared Island unit and civic-society planning for a future poll.
Sources & Methodology
Every poll on this page is attributed to the firm that ran it and shown to two decimal places, matching the precision each pollster published. Republic of Ireland unity figures are drawn from Red C, Ipsos MRBI, ARINS/Irish Times and the RTÉ Claire Byrne Live/Amárach series. Northern Ireland border-poll figures go back to the first post-Agreement poll in June 1998 and are drawn from LucidTalk (for the Belfast Telegraph), the ARINS project, the NI Life & Times Survey (ARK), the Institute of Irish Studies (University of Liverpool), Lord Ashcroft Polls and Ipsos Mori — all transcribed from Wikipedia's "Opinion polling on a United Ireland" page. The "Estimated Unity Sentiment" index at the top of this page is our own calculation: each of the NI, ROI-direct and ROI-aspirational series is interpolated into its own continuous trend, then the three trends are averaged at every year — it is a synthesis, not a poll in its own right. Demographic data is from the 2021 Census (NISRA).
United Ireland polls & the border poll. This page tracks support for a united Ireland and Irish reunification, including the latest border-poll polling in the Republic of Ireland, the 50% threshold that would make a poll likely under the Good Friday Agreement, and the changing religious and national-identity demographics of Northern Ireland from the 2021 census. Figures are updated as new polls from Red C, Ireland Thinks, Ipsos B&A and LucidTalk are published.