BELFAST (Reuters) - Northern Ireland’s cross-community Alliance Party won its first seat in the European Parliament in a surge it said furthered the case for a re-run of Britain’s Brexit referendum.

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Alliance leader Naomi Long took the second of three Northern Irish seats after campaigning for a second vote on Britain’s divorce from the European Union.

The British province, which voted to remain in the EU in the 2016 referendum but whose largest party props up the minority government in London and is an advocate of Brexit, returned more candidates in favor of staying in the EU than for leaving.

The vote also indicated increasing support for candidates not aligned to the traditional Catholic or Protestant voting blocs. It was the best national showing for the Alliance Party, which was founded almost 50 years ago, just as Northern Ireland’s violent period known as “The Troubles” deepened.

“This is a vote about Brexit ... it’s a vote to remain, it’s a vote to have a people’s vote,” Long, close to tears, told reporters at the Belfast count center.

“People came together behind Alliance to send a message and that message is we want to stay in the EU.”

Pro-EU Irish nationalists Sinn Fein and the pro-Brexit Democratic Unionist Party (DUP), which props up British Prime Minister Theresa May’s government, each retained the seat they held, in a sweep for female candidates.

Almost trebling the Alliance vote compared to the 2014 poll, to 18 percent, Long took the seat from the Ulster Unionist Party, to leave pro-British Unionist parties without a majority of Northern Ireland’s European seats for the first time.

Like Scotland, which also returned a majority of candidates seeking a Brexit rerun, Northern Ireland voted “remain” in the 2016 referendum but will leave with the rest of the UK after its citizens as a whole opted to quit the bloc.

How the 500-km (311-mile) border between Northern Ireland and EU member Ireland is managed after Brexit was one of the major obstacles that stopped May from ratifying in parliament the deal she reached with the EU.

Irish Prime Minister Leo Varadkar, who played a key role in that deal, which would keep the border open no matter how Britain leaves the EU, hailed Long’s election as a historic, pro-European vote which would be “heard across the continent”.

Northern Ireland still overwhelmingly votes along traditional lines two decades after a peace deal ended 30 years of sectarian violence, choosing mainly Catholic nationalists who favor a united Ireland or predominantly Protestant unionists who want to remain British.

Unionists also lost their majority at the last elections to the devolved assembly in 2017, however, and the Alliance were the biggest gainers at local council elections this month, closing the gap on the main blocs.

With some support slipping from the main Irish nationalist and pro-British parties, the votes of those moving towards cross-community parties like the Alliance and Greens could also prove crucial in any future referendum on reunification with Ireland.