The European Union accused Britain of playing a "stupid blame game" over Brexit on Tuesday after a Downing Street source said a deal was essentially impossible because German Chancellor Angela Merkel had made unacceptable demands. With just 23 days before the United Kingdom is due to leave the bloc, the future of Brexit remains deeply uncertain as both London and Brussels positioned themselves to avoid blame for a delay or a disorderly no-deal Brexit.

In a sign that Johnson's last-ditch proposals to bridge the Brexit impasse have failed, a Downing Street source said Merkel and Johnson spoke on Tuesday morning and she made clear that a deal was "overwhelmingly unlikely". The Downing Street source said that if Merkel's position on Northern Ireland remaining in the EU's customs union was the bloc's position, then a deal was impossible.

"If this represents a new established position then it means a deal is essentially impossible not just now but ever," the Downing Street source said. A spokesman for the German chancellor confirmed the call had taken place but declined to comment further. The EU was scathing. "Boris Johnson, what's at stake is not winning some stupid blame game," European Council President Tusk said on Twitter. "At stake is the future of Europe and the UK as well as the security and interests of our people. You don't want a deal, you don't want an extension, you don't want to revoke, quo vadis?"

Such abrupt remarks indicate the Brexit blame game has begun in earnest, and that now both London and European capitals are preparing for an acrimonious and potentially chaotic Brexit for which neither side wants to be held responsible. Johnson's spokesman said the British leader and Merkel had had a frank exchange and Britain had not seen any compromise from the EU. He said talks were at the critical point and it was not Britain talking about blame games.

A disorderly Brexit could rip apart the United Kingdom, endager the peace in Northern Ireland, hurt global growth and shape the future of the European Union which was built on the World War Two ruins of Europe. The pound was down 0.5% at $1.2226. An array of remarks by unidentified British sources laid bare just how far apart the two sides are after three years of tortuous haggling over the first departure of a sovereign state from the EU. Brexit talks are now reaching a critical moment, a British spokesman said in Brussels where Johnson's Brexit negotiator David Frost was in meetings with EU officials.