Boris Johnson's new adviser Dominic Cummings has told ministerial aides that he will fire any of them who leaked Cabinet papers in a new "one strike policy".

Mr Cummings told aides at meeting that there is a new "one strike policy" on leaks from Government. "He was firm - if you leak you are gone," one aide said.

Mr Cummings told the group of advisers that if any of them tried to take him to an employment tribunal "you will be dead to me", one source claimed.

The irony of the anti-leak drive itself leaking to The Telegraph may not be lost on Mr Cummings, a former adviser to Michael Gove and a key strategist on the victorious Vote Leave campaign during the 2016 EU referendum.

He was also played by the Hollywood actor Benedict Cumberbatch in a recent Channel 4 film of the referendum campaign.