Boris Johnson has been accused by a Cabinet Minister of running a 'Goodfellas government' by allowing aides to terrorise Whitehall like paranoid mob bosses.
And particular fury has been directed at the Prime Minister's 'obnoxious' right-hand man Dominic Cummings, with accusations that the senior aide is 'out of control'.
Referencing Martin Scorsese's 1990 Mafia movie starring Ray Liotta as a gangster who turns on his friends, the senior Minister told The Mail on Sunday: 'Cummings is behaving like a bald Ray Liotta at the end of Goodfellas.
No.10 mob: How Dominic Cummings, Boris Johnson and Chancellor Sajid Javid might look in a Goodfellas poster
'This should be the glory days but instead No 10 has slipped into paranoia, trusting an ever smaller number of people and sometimes not even each other.
'He's hearing police helicopters in his head.'
The astonishing outburst comes after a torrid month in Whitehall that has seen Mr Cummings order substantial leak inquiries into Cabinet Ministers and aides after a significant detail from Cabinet and the National Security Council appeared in print.
Letters have been sent to Cabinet members warning them against speaking to the Press.
However, Government aides are furious that leaks believed to have originated from No 10, regarding Huawei and HS2, have not sparked similar probes.
Critics suggest Mr Johnson is unlikely to be able to clamp down, due to his own record as Foreign Secretary, when Theresa May's allies believed his team were behind a slew of damaging leaks about Brexit. One former May adviser said: 'It was Boris that let this genie out of the bottle.'
Other members of the Cabinet have also accused Mr Cummings of leaking when he worked as an adviser to Michael Gove from 2010 to 2014.
At the time, then Prime Minister David Cameron called Mr Cummings a 'career psychopath'.
Amid concern about 'mob-handed' treatment, there has also been widespread anger at the 'destabilising threat' of a major Whitehall reorganisation and briefings regarding a Cabinet cull. Planned changes have been scaled back as a result.
A separate Cabinet Minister told this newspaper: 'Just when things were getting back to normal after the endless uncertainty of Brexit, they plunge everyone into more chaos.'
It is understood that a number of aides have taken legal advice ahead of a rumoured 'purge' of special advisers next month.
Mr Cummings has bypassed standard Whitehall hiring protocol by calling for 'weirdos' to apply to work for him.
On Friday, he told a No 10 meeting that 35,000 people had applied but a lot 'are indeed weirdos'.