The UK is currently in a transition period under which it must follow most EU regulations, following its legal withdrawal from the bloc on 31 January.

Both sides exchanged legal text on a future trade deal in March. After the negotiations this week, a fourth round of talks is scheduled to begin on 1 June.

Under the UK’s withdrawal agreement with the EU, both sides currently have until 31 December to ratify a trade deal and rules for future co-operation.

An extension to the December deadline should be made by the UK-EU “joint committee” overseeing the agreement by 1 July.

Opposition parties including the Liberal Democrats and the SNP have both called on the UK government to extend the transition period beyond December.

Shortly after becoming Labour leader last month, Sir Keir Starmer said the UK should prolong talks beyond December if “necessary to do so”.

He added that the December deadline was “going to be very, very tight,” and he thought it “unlikely” the government would finish talks in time.

But the government insists it is committed to agreeing a deal by December 2020, and an extension would simply prolong disruption for businesses.