Esther McVey, Theresa Villiers and Andrea Leadsom are some of the MPs to be unceremoniously dumped from government.
Leadsom said it had been a “real privilege” to spend six years in government, adding: “I will continue from the back benches to work to ensure everyone is treated with dignity and respect.”
Villiers said: “What the prime minister giveth, the prime minister taketh away: just over six months ago, I was delighted to be invited by the prime minister to return to government after three years on the backbenches.
“This morning he told me that I need to make way for someone new.”
Fellow former Tory leadership contender McVey said she was “very sorry to be relieved of my duties”.
Cox made clear he had been sacked, rather than choosing to leave his role, saying: “I am now leaving the government at the PM’s request.”
Julian Smith was also been dumped from the Northern Ireland Office – despite brokering the deal which restored the powersharing administration in Stormont.
Smith said it had been “the biggest privilege” to serve the people of Northern Ireland and he was “extremely grateful” to have been given the chance to serve “this amazing part of our country”.
Speculation about Smith’s position centred on the terms of the Stormont deal, amid Tory concerns it could pave the way for prosecutions of British soldiers.
But allies of the axed minister said it was “absolute crap” to suggest that Johnson and Number 10 had not been kept informed of the process and details of the deal.
Culture secretary Baroness Morgan has already said she intends to leave her ministerial role, Chris Skidmore indicated he had left his post as universities minister to have “more time to spend” with his child and George Freeman said he was “on my bike” after losing his transport job.
Nus Ghani also joined Freeman in departing the Department for Transport.
The biggest shock announcement, however, came from the loss of chancellor Sajid Javid, who resigned after being asked to sack all of his ministerial aides.
Home secretary Priti Patel, foreign secretary Dominic Raab, chancellor of the duchy of Lancaster Michael Gove, justice secretary Robert Buckland, international trade secretary Liz Truss and health secretary Matt Hancock were all confirmed in their existing roles.
Downing Street has previously confirmed that Grant Shapps will stay on as transport secretary.