Donald Tusk has hit out at the Prime Minister in a tweet, accusing him of engaging in a "stupid blame game".
The European Council president warned Boris Johnson that he was risking the future relationship between Europe and the UK, as Brexit talks reportedly come close to collapse.
"What's at stake is not winning some stupid blame game. At stake is the future of Europe and the UK as well as the security and interests of our people," he wrote.
"You don't want a deal, you don't want an extension, you don't want to revoke, quo vadis?".
Responding to Mr Tusk's Twitter post, Brexit Party MEP Lance Forman said Britain would "do brilliantly" without the EU.
"Keep sweating Donald. Britain will do brilliantly with a no-deal Brexit and then all and sundry will see how irrelevant your corrupt and wasteful organization [sic] has become and will join us," he wrote.
"The EU's time on this earth is coming to an end - game over. Enjoy it while it lasts."
Boris Johnson is yet to respond to the EU official's tweet.
Mr Tusk's comments came as Downing Street sources claimed German chancellor Angela Merkel had made clear that an agreement was now "overwhelmingly unlikely".
Following a telephone call with Boris Johnson, she was said to have insisted the Irish must have a veto over Northern Ireland leaving the customs union.