Britain will find it “impossible” to negotiate a comprehensive and close future relationship with the EU by Boris Johnson’s December deadline, the new head of the European Commission warned today.

In a stark message to the prime minister before talks this afternoon Ursula von der Leyen said that the price of the clean-break Brexit would be a “distant” partnership with the EU and new barriers to trade.

She added that even this would be difficult to achieve without an extension to the transition period, which has been ruled out by Mr Johnson.

Instead she said that the issues to be resolved would have to be “prioritised”, setting the scene for an early confrontation between the two sides in deciding which areas of future co-operation to