A series of parliamentary private secretaries, and even the Solicitor General, also handed in their resignations on Tuesday night.
Are they a sign of more resignations to come from across the Government?
Here is the list so far:
Alex Chalk, Solicitor General
With great sadness I am resigning as Solicitor General. I won’t be doing media interviews. pic.twitter.com/8kr9ecRECg
— Alex Chalk (@AlexChalkChelt) July 5, 2022
The most high-profile of the resignations from outside of the Cabinet, Mr Chalk said that he could not “defend the indefensible”.
Theo Clarke, Trade Envoy to Kenya
The Stafford MP resigned from her position as trade envoy to Kenya with a statement which said she takes “allegations of sexual misconduct very seriously” and that the Prime Minister had shown a “severe lack of judgment and care” for his parliamentary party.
Jonathan Gullis, Parliamentary Private Secretary to the Secretary of State for Northern Ireland
In a statement, Mr Gullis tendered his resignation “with a heavy heart”, adding that his party has been “more focused on dealing with our reputational damage rather than delivering for the people of this country”.
Virginia Crosbie, Parliamentary Private Secretary at the Welsh Office
Ms Crosbie said in a Facebook post that if Mr Johnson is left in office, he will “irrevocably” harm the Government and the Conservative Party.
Andrew Murrison, Trade Envoy to Morocco
In a letter calling for Mr Johnson to resign, Mr Murrison quit his job, saying that the PM’s position had become “unrecoverable”.
Nicola Richards, Parliamentary Private Secretary to the Department for Transport
Ms Richards said in a statement that she could not serve “under the current circumstances”.
Bim Afolami, Conservative Party Vice Chair
Speaking to Talk TV, Mr Afolami announced that he too would have to step down, adding: “I just don’t think the Prime Minister any longer has, not just my support, but he doesn’t have, I don’t think, the support of the party, or indeed the country any more.”
Saqib Bhatti, Parliamentary Private Secretary to the Health Secretary
Mr Bhatti quit his role with a statement that “recent events have undermined trust and standards in public life”.