Post-Brexit talks in last push until Sunday

"We gained a clear understanding of each other´s positions. They remain far apart," the commission chief said, despite months of negotiations on how future trade ties should look like once the UK breaks all ties with the bloc at the end of the year.

Negotiating teams will continue to try to bridge the gaps in the coming days, and a decision will be made by the end of the week on whether there is a possibility for a deal or not.

The main sticking points are fishing rights in British waters, ensuring fair competition for companies on both sides, and ways to solve future disputes.

German chancellor Angela Merkel earlier on Wednesday told German lawmakers that the integrity of the single market cannot be compromised.

"If there are conditions coming from the British side which we cannot accept, then we will go on our own way without an exit agreement," she said.

The EU wants to make sure that the UK cannot undercut its businesses and follows EU standards, something Johnson said that "no British prime minister could accept".

The EU's aim is to manage the future divergence in environmental, social and labour standards, which are currently shared, while the UK insists on its sovereignty in setting up its own standards.

Von der Leyen is expected to update EU leaders on the status of the talks as they meet for a summit in Brussels on Thursday.

The German commission chief met Johnson in the Berlaymont building and as the two leaders posed for pictures von der Leyen warned Johnson to "keep [your] distance", reminding him of Covid regulations.

She told Johnson he should remove his masks for the pictures and then "put it back on immediately."

"You run a tight ship here, Ursula, and quite right too," Johnson quipped in return.

The mood of negotiations has soured over the last weeks, as both sides have increasingly called on the other to compromise ahead of the Brussels meeting.

The transition period, that ends on 31 December, meant that most rules covering trade, travel and businesses have been the same as when the UK was still a member of the bloc.

No deal on future relations - including zero tariffs and zero quotas - could hit firms hard on both sides, with the British economy expected to suffer the bigger blow.

In a small sign of optimism, the two sides had agreed on arrangements earlier this week for the border between Northern Ireland and the Republic of Ireland.

Britain said it would remove bits in legislation that were in breach of the exit treaty governing the border issue.