Theresa May is meeting the EU’s chief Brexit negotiator for talks in Downing Street in the run-up to a crucial summit of the remaining 27 EU members.

The prime minister is having a working dinner with Michel Barnier and European Commission President Jean-Claude Juncker in No 10.

On Saturday, EU leaders meet to agree their key negotiating principles based on draft guidelines issued last month.

Official talks will not begin until after the general election on 8 June.

The UK is on course to leave the EU in March 2019, after Mrs May triggered Article 50 last month.

Mr Barnier, a former EU Commissioner, has said Brexit negotiations must be concluded within 18 months to allow for any settlement to be approved by the UK, other EU members and the European Parliament.

The EU wants the terms of the UK’s exit to be decided before any discussion of a future trade relationship while Mrs May wants to the two issues to be dealt with simultaneously.

Amid continued speculation about the size of the so-called “divorce bill” the EU is seeking, former PM David Cameron said he hoped that the two sides would be able to agree a figure early on in the negotiations.

Speaking at a conference in Thailand, he said “of course we accept some liabilities for this membership we’ve had for 40 years, just as we have a claim on some of the assets that we’ve paid into”.

“And I think we can settle the principles of that and then get on with the nature of the relationship.”