Mrs May, who is currently on a walking on holiday in Switzerland, was "unimpressed" with Dr Fox's behaviour and wants her ministers to "stop wasting time" and instead focus on delivering Brexit.

"She does not stand for any of that nonsense," the source said. "She is not happy. They have got plenty to get on with"

The source also denied claims that she could delay triggering Article 50 and beginning the formal process of leaving the European Union.

Reports at the weekend suggested that the Government is planning to delay invoking Article 50 until 2017, meaning Brexit would not take place until the end of 2019.

A source insisted that she will push "full steam ahead" and invoke Article 50 at the beginning of next year. "She is not taking her foot off the pedal," the source said.