Prime Minister Theresa May unveiled details of her plan to protect the rights of EU nationals living in Britain on Monday, saying the government would work to offer them largely the same benefits as British citizens, Reuters reported.
An agreement on the post-Brexit rights of EU nationals is one of the easier issues for the two sides to settle, with both Britain and the rest of the bloc wanting to provide assurances to millions of their citizens living abroad.
But the EU's top negotiator Michel Barnier said Britain needed "more ambition, clarity and guarantees" in its position. "EU goal on citizens rights: same level of protection as in EU law," he said in a tweet.
Reflecting the complexity of family relationships born of more than 40 years of EU membership, some lawmakers demanded clarity on what the changes meant for EU citizens' family members and spouses from non-EU states.
And a major sticking point, which Brexit minister David Davis said at the weekend would be the row of the summer, was that Britain would not defer to rulings from the European Court of Justice - an institution the EU says must be involved.
"I want to completely reassure people that under these plans, no EU citizen currently in the UK lawfully will be asked to leave at the point the UK leaves the EU. We want you to stay," she told a rowdy session of parliament, adding some detail to a proposal made to Brussels on Friday.
"I believe it is a generous offer."
May made her pitch just hours after winning a deal to prop up her minority government with Northern Ireland's Democratic Unionist Party, necessary to give her a better chance of passing laws to ease the path of Brexit during two years of talks.
But her authority is weakened and her strategy for Brexit is openly challenged both inside and outside her party, after she lost her parliamentary majority in an election she did not have to hold. The EU is determined to press home its advantage.