Barnier, the EU’s chief negotiator, said there was "nothing surprising whatsoever about the EU's priorities" in the negotiations, which remain stuck on key issues including access to the UK’s fishing waters, state aid rules and a so-called ‘level playing field’ on environmental and social standards.
His opposite number, David Frost meanwhile signalled his own frustration with the discussions as he urged EU leaders to accept the “reality” of the UK’s position.
Failure to strike a deal, which the EU wants done by October, would leave the two sides trading on World Trade Organisation terms, imposing a host of tariffs and quotas once the current transition period covering their relationship expires at the end of this year.
Speaking at a press conference on Friday, a visibly exasperated Barnier said the EU was focused on "protecting thousands of jobs in our Member States”.
He said of the impasse: “It’s about workers' rights, it's about consumer rights, and it’s about health and protecting our environment".
And he warned that a deal now seems “unlikely” as he revealed that the EU will begin a "virtual tour" of Member States to get them ready for a no-deal outcome.
Barnier said, “Too often this week, it felt as if we were going backwards more than forward. Today at this stage an agreement between the UK and the European Union seems unlikely. I still do not understand why we are wasting valuable time”.
“Too often this week, it felt as if we were going backwards more than forward. Today at this stage an agreement between the UK and the European Union seems unlikely. I still do not understand why we are wasting valuable time” Michel Barnier
"We hear the British Government's concern about maintaining its sovereignty and its regulatory autonomy and we respect that, clearly. But no international agreement was ever reached without the parties agreeing to common rules — no international agreement.
"And I can predict, with absolute certainty, this will also be the case of trade agreements between the UK and other partners in the future such as the United States, Japan and Australia.”
Barnier added: "Apart from the question of a level playing field there are still many other areas where progress is needed and for example, obviously fisheries where we have made no progress whatsoever on the issues that matter."
For the UK side, Frost - who reportedly shared a draft agreement with EU negotiators in a bid to break the deadlock - said Britain was still aiming for a deal.
“Agreement is still possible, and it is still our goal, but it is clear that it will not be easy to achieve,” he said.
And the chief British negotiator added: “Substantive work continues to be necessary across a range of different areas of potential UK-EU future cooperation if we are to deliver it. We have had useful discussions this week but there has been little progress.
“The EU is still insisting not only that we must accept continuity with EU state aid and fisheries policy, but also that this must be agreed before any further substantive work can be done in any other area of the negotiation, including on legal texts.
“This makes it unnecessarily difficult to make progress.... We have been clear from the outset about the principles underlying the UK approach.”
“Substantive work continues to be necessary across a range of different areas of potential UK-EU future cooperation if we are to deliver it. We have had useful discussions this week but there has been little progress" David Frost
Frost added: "We are seeking a relationship which ensures we regain sovereign control of our own laws, borders, and waters, and centred upon a trading relationship based on an FTA like those the EU has concluded with a range of other international partners, together with practical arrangements for cooperation in areas such as aviation, scientific programmes, and law enforcement.
"When the EU accepts this reality in all areas of the negotiation, it will be much easier to make progress."
Barnier meanwhile dismissed the UK’s draft proposals, saying that while it was “always a useful thing for the UK to remind us of their position”, the bloc could “only work on a consolidated text if everyone does it together”. And he warned: "We can't have everyone working on a unilateral basis."
With the next round of Brexit talks set to start on 7 September, Barnier warned, "the clock is ticking".
Commenting on the talks, Former British Socialist MEP Richard Corbett said, “Remember, the Brexiteers promised us that this would be the easiest deal in history and said that Britain held all the cards... Looks like Brexit was sold on false pretences”.
French Renew Europe MEP Pierre Karleskind warned that with the talks stalling again, the EU should “prepare for the worst” possible outcome on fisheries. The l chair of the European Parliament’s Fisheries Committee said, “A balanced fisheries agreement remains a priority for the European Union. [But] We must now prepare for the worst. I will push for a significant support for fisheries within the €5bn Brexit fund”.
German socialist deputy Bernd Lange lashed out at Boris Johnson saying the UK Prime Minister was, “playing with the fire of a ‘No Deal’. He warned that under Johnson’s leadership, the UK was increasingly deviating from the joint political declaration which set out the framework for the future relationship between the EU and the UK.
Lange added, “When will ideological populism finally be overcome and the attempt to undermine workers' rights, consumer protection and environmental standards in the name of British sovereignty be abandoned?”