Image copyright Getty Images

Prime Minister Theresa May will return to Brussels later to continue Brexit talks with the European Union.

She is trying to renegotiate the Irish backstop - the insurance policy to prevent the return of customs checks on the Irish border.

Mrs May is expected to request legally-binding assurances that the backstop will not extend indefinitely.

However, European Commission President Jean-Claude Juncker has said he does not expect a "breakthrough" in talks.

The backstop policy is part of the withdrawal agreement Mrs May agreed with the EU, and became one of the main reasons her Brexit deal was voted down in Parliament in January.

Critics fear it would leave the UK tied to a customs union with the EU indefinitely and see Northern Ireland treated differently.

MPs gave their backing for Mrs May to renegotiate the policy in a vote earlier this month and said she was "working hard to secure the legally binding changes" that Parliament wants.

But the EU has consistently refused to make changes.

Chancellor Philip Hammond said on Tuesday evening the government accepted the EU will not agree to replace the backstop arrangements for the Irish border with technological alternatives in time for the scheduled date of Brexit on 29 March.

The so-called "Malthouse Compromise" - proposed by Remainers and Leavers - included proposals to use technology and checks away from the border to ensure the backstop was never activated.

But Mr Hammond said he hoped the technological solution would form part of negotiations over the following 21 months on the UK's future relationship with the EU.

He added that legally-binding changes to ensure the backstop does not become permanent "would deliver the core of a majority for a deal in the House of Commons".

Leading Brexiteers Jacob Rees-Mogg and Steve Baker insisted they were happy with this arrangement, saying the Malthouse proposals were "alive and kicking".

Media playback is unsupported on your device Media caption Confused by Brexit jargon? Reality Check unpacks the basics.

Jeremy Corbyn also announced he would be going to Brussels to meet the EU's chief negotiator, Michel Barnier, on Thursday.

The Labour leader said they would discuss his party's Brexit proposals - including a permanent customs union and a strong relationship with the single market - and that it was a "necessity" to take no deal off the table.

Brexit Secretary Stephen Barclay updated the Cabinet on talks with Mr Barnier on Tuesday.

The meeting, on the issue of the Irish backstop, was described as "productive" but Mr Barnier "expressed concerns".

At the time, a European Commission spokesman said: "The EU27 will not reopen the withdrawal agreement.

"We cannot accept a time limit to the backstop or a unilateral exit clause - and further talks will be held this week to see whether a way through can be found that would gain the broadest possible support in the UK parliament and respect the guidelines agreed by the European Council."

The PM has promised that if she is unable to negotiate an amended deal by 26 February then she'll return to Parliament and allow a further day of debate, with further chances for MPs to vote, the following day.