The leader of the SDLP has called for a post-Brexit referendum on creating a united Ireland.
Colum Eastwood said the planned withdrawal had made a border poll a lot more winnable.
EU leaders have agreed if there is a vote for a united island then Northern Ireland can automatically rejoin the bloc.
Mr Eastwood said: "I think there is now a route for actually winning a border poll.
"I think that we need to have one after Brexit, when the dust settles."
The nationalist party is a staunch opponent of Brexit, which was rejected by 56% to 44% in Northern Ireland during last year's vote.
Mr Eastwood said unionists were part of his vision for the future of a "reconciled Ireland".
He added: "A border poll is no longer solely the project of Irish nationalism but of pro-European internationalism.
"A unity referendum now has a much broader reach, offering us a return to the EU as a sovereign country."
The SDLP launched its manifesto for the 2017 General Election in South Belfast on Tuesday.
The area, a diverse mixture of leafy suburbs, student housing and a relatively small number of loyalist estates, voted strongly for remain.
Dr Alasdair McDonnell, the SDLP's veteran incumbent, is fighting to retake the seat and Mr Eastwood characterised it as a race between his party colleague and a hardline Brexiteer from the Democratic Unionists.
The SDLP is arguing that only it can effectively fight Brexit because the DUP supports it, while Sinn Fein, which is also strongly against, does not take its seats at Westminster and is aligned with obscure parties like the Communists of Bohemia in the European Parliament.
Sinn Fein has called for a vote on Irish unity within five years.
Party president Gerry Adams said: "The imposition of Brexit underlines the undemocratic nature of partition and its impact on citizens, the economy, and public services.
"A unity referendum is an opportunity for the people to have their say and to build a new, united, and agreed Ireland."
The SDLP is defending three seats held by former leaders Dr McDonnell in South Belfast, Margaret Ritchie in South Down and Mark Durkan in Foyle.
Mr Eastwood criticised Sinn Fein's refusal to take its Westminster places.
"The only way to take a stand in this election is to take your seats.
"Shouting from the sidelines will make no difference."
He said with the polls increasingly tightening and the possibility of another hung Parliament, every seat and every vote came into focus.
Mr Eastwood said because of the inability of local politicians to resume powersharing, the DUP and Sinn Fein were offering permanent Tory governance.
"The political maths of this election is simple: a DUP seat will only add to Tory numbers - a Sinn Fein seat won't even get counted.
"And with devolved deadlock, that means people like Jeremy Hunt, Iain Duncan Smith and others slowly taking over our public services."