“What I’m going to be setting out today is clearly how the UK proposes to protect the rights of EU citizens in the UK, and see the rights of UK citizens living in Europe protected,” May said as she arrived at the two-day meeting of EU leaders.

“That’s been an important issue, we’ve wanted it to be one of the early issues that was considered in the negotiations, that is now the case, that work is starting.

“We will be setting out how we propose to ensure that EU citizens living in the UK have their rights protected in the United Kingdom.”

May’s spokesman earlier said that she would set out the principles of her plan over dinner with other EU leaders on Thursday evening.

EU officials said they had however asked her not to bring up the issue, saying all talks should be conducted by official EU and British negotiators Michel Barnier and David Davis, and not by national leaders.

The fate of an estimated three million Europeans currently living in Britain and around one million Britons living elsewhere in the EU was thrown into doubt by Britain’s vote to leave the bloc last year.

May had previously refused to guarantee the rights of EU citizens in Britain until those of expatriate Britons were secured.

The issue of citizens rights is one of three priorities in the Brexit talks which began on Monday, along with Britain’s divorce bill and the fraught question of Northern Ireland, which will share Britain’s only land border with the EU after Brexit.

May said the talks had made a “very constructive start”.