LONDON (AP) — British Prime Minister Theresa May Friday used a speech in Northern Ireland to tout her latest Brexit plan as providing a “bright future” for Northern Ireland that would maintain peace and safeguard jobs.

The embattled British leader is urging European Union leaders to take a more flexible view on how to solve the Irish border issue, a key sticking point in talks on Britain’s exit from the bloc, which is expected in March.

She is vehemently opposed to an EU “backstop” proposal that would keep Northern Ireland inside a customs union with the EU while the rest of the UK leaves. She said no prime minister could accept an arrangement that threatened the unity of the United Kingdom and imposed a sea border between Northern Ireland and the UK.

May is hoping the EU negotiating team will respond positively to plans her government spelled out last week that call for a “common rule book” to govern trade in goods but not services between Britain and the EU after Brexit.

She says this would keep “frictionless” trade and make a border between the Republic of Ireland — an EU member — and Northern Ireland unnecessary. She argued that it would also protect the gains of the Good Friday peace accord signed 20 years ago.

“In the Northern Ireland of today, where a seamless border enables unprecedented levels of trade and cooperation North and South, any form of infrastructure at the border is an alien concept,” May said.

The prime minister said a seamless border is “the foundation stone” of the peace agreement that ended decades of violence and that undermining it would be a betrayal.

EU leaders have long said Britain cannot “cherry pick” which aspects of its relationship with the EU it wishes to keep in place after Brexit. The new proposals by May’s government are seen by some as doing just that, and the EU response has thus far been lukewarm.