Totnes MP Anthony Mangnall is another name in a growing list of Conservative backbenchers to retract their support for the prime minister.

In a Tweet earlier today Mr Mangnall said:

“Standards in public life matter.

At this time I can no longer support the PM.

His actions and mistruths are overshadowing the extraordinary work of so many excellent ministers and colleagues.

I have submitted a letter of no confidence.”

The PM has been having a hard time avoiding the ‘partygate’ narrative this week despite flying thousands of miles away in a bid to calm tensions between Russia and the Ukraine.

More allegations against Mr Johnson surfaced this week, with newspapers reporting he was inside his flat for a gathering which is currently being investigated by police.

It is one of twelve events subject to criminal investigations by the Metropolitan Police, which launched its own probe after being passed evidence by Sue Gray - the civil servant who was conducting an internal inquiry into ’partygate’.

So far ten MPs have publicly called on the PM to resign and its understood there may be many more quietly hoping he can be removed.