The European Union is beefing up its preparations for a ‘no deal’ Brexit, more than doubling the number of officials devoted to preparing for a breakdown in the talks, the Sunday Telegraph has learned.

EU sources said the number of officials in the European Commission secretariat focussing on preparations for either a ‘no deal’ scenario or a 'hard Brexit' would expand from eight to 20 as concerns mount in Europe over whether Theresa May can deliver.

The decision to grow the unit was in part a reflection of growing anxiety in Brussels that political divisions in the UK may make a deal impossible, EU sources said, particularly given the UK’s commitments to avoid a hard border in Northern Ireland.

“The overall optimism that there can be a deal has decreased in the Commission given the events of this month,” said a senior EU source.

Pressure is increasing daily on Mrs May to define what kind of future relationship the UK will seek with Europe after Brexit, with her cabinet now in open warfare over what direction to take.