Nadine Dorries is to stand down as Culture Secretary and return to the Conservative backbenches.
She wrote in a statement on Tuesday: "I have submitted my letter of resignation to the outgoing Prime Minister.
"I am humbled that Liz Truss extended her confidence in me by asking me to remain as Secretary of State for DCMS.
"I will always show her the same loyalty and support I have to Boris Johnson. Onwards!"
This comes after Liz Truss has been elected Conservative Party leader and has promised a “bold plan” to cut taxes, deal with the energy crisis and deliver a Tory victory in 2024 as she prepares to take office as the country’s next prime minister.
Nadine Dorries
Stefan Rousseau
She defeated rival Rishi Sunak by 81,326 votes to 60,399 to win the Tory leadership, and will replace Boris Johnson in No 10 on Tuesday.
Ahead of an expected reshuffle, Priti Patel said she would be resigning as Home Secretary and returning to the backbenches after Ms Truss takes office.
Cabinet Office Minister Nigel Adams, another Johnson loyalist, is also standing down.
Ms Truss used her victory speech to say Tory beliefs in freedom, low taxes and personal responsibility “resonate with the British people”.
“During this leadership campaign, I campaigned as a conservative and I will govern as a conservative,” she said.
“We need to show that we will deliver over the next two years.
“I will deliver a bold plan to cut taxes and grow our economy.
“I will deliver on the energy crisis, dealing with people’s energy bills but also dealing with the long-term issues we have on energy supply.”
She promised Tory members “we will deliver a great victory for the Conservative Party in 2024”.
Mr Johnson will depart No 10 on Tuesday and Ms Truss will fly to Balmoral to meet the Queen for the formal handover of power.