UK government sources have said that EU leaders have to intervene to break the deadlock in post-Brexit trade talks, as officials from the bloc have described reaching an agreement as a "long shot", the Telegraph reported on Sunday.
“Ahead of round three, there needs to be a political injection on the EU side to move the negotiations forward, particularly on this issue of a level playing field", the anonymous cabinet member said.
Another source accused the EU negotiators of not being used to the dynamic of the UK "standing up for itself" and refusing to drop unworkable proposals "just to keep talks going".
This follows comments by David Frost, Britain's chief negotiator, who described their demands on overfishing and "level playing field" rules as unacceptable.
Following the second formal round of trade talks, Michael Barnier, the EU's chief negotiator, said on Friday that the UK did not "wish to commit seriously on a number of fundamental points".
Mr Frost replied, saying that the EU was making demands that were unlike those seen in other free trade deals "and we will not agree to it here".
Krisjanis Karins, Latvia's prime minister, described the idea of establishing a workable trade agreement within the established timeframe as "not impossible" but that a basic deal was a "long shot".
He added that European leaders were currently "preoccupied" with the Covid-19 pandemic sweeping across the continent.
"We've talked about internal trade, we've talked about protective equipment, we've talked about everything. We simply are not able to turn to that issue", he said.
"We need an agreement but we need a good agreement for everyone. It has to be one of these win-win kind of things that is good for the Brits and good for the EU. Everyone knows that that entails a lot of practical issues that often need time to be resolved", he added.
"I'll say it this way, I think it's a long shot to get a good deal by the end of June right now. It's probably not impossible to get a deal but to get a good deal. And then it's an open question, would both sides be open to looking to potentially extend this in order to get a good and clear deal?"
Despite the impasse, UK Prime Minister Boris Johnson has ruled out extending the transitional period which will officially come to an end on 31 December this year.
Any extension of the Brexit transitional period, which maintains the UK within the EU's Customs Union and Single Market but formally outside of the political union, could be problematic for Boris Johnson, who was elected on the promise of finalising the Brexit process.
