European leaders have said Northern Ireland could easily rejoin the EU after Brexit if it votes for Irish reunification.
In a move that may anger unionists, diplomats are reportedly preparing to ask the other 27 EU members to endorse the idea at a summit on Saturday.
Although Sinn Fein has campaigned for a “united Ireland” since the establishment of the Irish Free State in 1922, the predominantly Protestant residents of Northern Ireland have remained against it.
This tension led to the militancy of the IRA and the Troubles for three decades before the signing of the Good Friday agreement in 1998.
Under the terms of the agreement both Britain and Ireland are committed to holding a referendum on the subject if there is a popular will for reunification within Northern Ireland.
The theory is that it will be similar to the reunification of East and West Germany after the end of the Cold War in 1990.
The move would prevent the return of a hard border between the two countries – a serious fear among people in Northern Ireland who believe it would increase the risk of violence in the country.
But increased talk of Irish reunification has stoked fears in Westminster about the potential break up of the UK under the stress of Brexit.
UK news in pictures
UK news in pictures
1/18 23 June 2017
British Prime Minister Theresa May addresses a news conference at the EU summit in Brussels, Belgium, June 23, 2017
2/18 22 June 2017
Cosplay fans (L-R) George Massingham, Abbey Forbes and Karolina Goralik travel by tube dressed in Harry Potter themed costumes, after a visit to one the literary franchise's movie filming locations at Leadenhall Market in London, Britain
3/18 22 June 2017
Racegoers cheer on their horse on Ladies Day at the Royal Ascot horse racing meet, in Ascot, west of London
4/18 21 June 2017
A reveller walks among the tipi tents at the Glastonbury Festival of Music and Performing Arts on Worthy Farm near the village of Pilton in Somerset, South West England
5/18 20 June 2017
A police officer lays some flowers passed over by a member of the public, close to Finsbury Park Mosque in north London, after one man died and eight people were taken to hospital and a person arrested after a rental van struck pedestrian
The Borough Market bell is seen in Borough Market in central London following its re-opening after the June 3 terror attack
Two women embrace in Borough Market, which officially re-opens today following the recent attack, in central London
Mayor of London Sadiq Khan attends the re-opening of Borough market in central London following the June 3 terror attack
People walk through Borough Market in central London following its re-opening after the June 3 terror attack
News Corp CEO Rupert Murdoch, with one of his daughters, visit Borough Market, which officially re-opened today following the recent attack
A woman reacts in front of a wall of messages in Borough Market, which officially re-opened today following the recent attack, in central London
Vivenne Westwood walks the runway at the Vivenne Westwood show during the London Fashion Week Men's June 2017 collections
Millwall fan and London Bridge hero Roy Larner on 'Good Morning Britain'
Richard Arnold, Roy Larner, Piers Morgan and Susanna Reid on 'Good Morning Britain'
15/18 11 June 2017
England players celebrate after defeating Venezuela 1-0 to win the final of the FIFA U-20 World Cup Korea 2017 at Suwon World Cup Stadium in Suwon, South Korea
16/18 11 June 2017
England players celebrate with the trophy after the final match of the FIFA U-20 World Cup 2017 between Venezuela and England at Suwon World Cup Stadium in Suwon, South Korea
17/18 11 June 2017
Great Britain's Alistair Brownlee celebrates winning the Elite Men Columbia Threadneedle World Triathlon Leeds
Danny Lawson/PA Wire
18/18 11 June 2017
Two men drink beer outside the Southwark Tavern which reopened for business today next to an entrance to Borough Market which remains closed in London
Scottish First Minister Nicola Sturgeon has already called for a new independence referendum after the country voted overwhelmingly for Remain.
She argued that the Brexit vote constitutes a “material change” in Scotland’s circumstances within the union – which would justify a fresh vote under the terms of the Edinburgh agreement signed by David Cameron and Alex Salmond in 2014.
The meeting in Brussels will lay out the formal adoption of EU guidelines for exit negotiations with the UK.
The leaders are expected to take tough opening stances on certain issues such as the rights of EU migrants within the UK and the future of Gibraltar as well as Northern Ireland.
The other EU leaders are keen not to appear to go too easy on the UK as it leaves for fear that it may encourage the Eurosceptics in their own countries to push for a referendum.
Irish Taoiseach Enda Kenny has called for a commitment to a “united Ireland” to be included in the final Brexit treaty.
But a UK government source rejected the move for Irish reunification, telling the Financial Times: “Northern Ireland’s constitutional position as part of the UK is based firmly and clearly on the freely given consent of its people. The UK government has consistently upheld the principle of consent regarding Northern Ireland’s future.
“It is clear that the majority of the people of Northern Ireland continue strongly to support the current political settlement, including Northern Ireland’s continuing position within the UK.”Reuse content