Two serving Government ministers are among the Conservative MPs who have announced they will not seek re-election on the first day of the General Election campaign.
Transport minister Huw Merriman and work and pensions minister Jo Churchill shared resignation letters featuring the House of Commons letterhead on Thursday.
Rishi Sunak’s decision to call a summer election surprised many in Westminster, who had been expecting an autumn poll.
The news has reportedly caused disquiet among some Tory MPs fearful of losing their jobs, and newspaper reports have suggested Cabinet ministers voiced concerns about the decision.
Other MPs who have already said they will not stand are having to say goodbye to Parliament sooner than expected.
Ms Churchill cited “family reasons” in her resignation letter, and said she had the “utmost respect for the difficult job” of the Prime Minister.
In his letter, Bexhill and Battle MP Mr Merriman did not specify a reason for his departure but thanked his staff, local Conservative association and the Prime Minister, and paid tribute to his constituency.
In a transport-themed sign-off, he added: “Thank you to all of the amazing people I have met on my journey. I will miss everything but, as I sit in the political departure lounge, I am looking forward to a new journey (whatever that might be).”
Dame Eleanor Laing, the Deputy Commons Speaker who was elected as a Conservative MP but relinquished party affiliation to take up her role, also announced she would stand down.
The MP for Epping Forest, who has served for 27 years, said in a post on X that she had informed Mr Sunak “several days ago”.
She was close to tears in the Commons chamber as she thanked MPs for their tributes following the announcement, and said she was leaving the “best job in the world”.
Conservative former minister Sir Michael Ellis was among those not seeking selection.
The Northampton North MP, who has served in several prominent ministerial positions including as attorney general, said it was an “extremely difficult decision” not to stand again.
Among his “lasting legacy” achievements, he counted the “Diamond and Platinum Jubilee gifts I arranged for the late Queen” on the Parliamentary estate, and a plaque to commemorate former prime minister Spencer Perceval, a Northampton MP, and the only premier to have ever been assassinated.
James Grundy, the Tory MP for Leigh since 2019, meanwhile told his local newspaper he would not feature on the ballot paper.
Mr Grundy, the first ever Conservative MP for the constituency, said the pandemic, the war in Ukraine, and the death of Queen Elizabeth II were among the events which made his time in the Commons “the most challenging Parliament since the one that sat during World War 2”.
He added there had been a “saddening change in the political climate” as he expressed concerns about security threats faced by MPs, their families, and staff.
Labour MP for Makerfield Yvonne Fovargue also announced her intention not to stand again, saying it was the “right time” to step down.
Labour former minister Kevan Jones said in a letter announcing his decision not to stand it would be “impossible” for him to fight the campaign as he is undergoing surgery in early June for “an ongoing condition”.
The North Durham MP described his decision as “difficult”, adding: “I am sad to be leaving the House of Commons but would like to thank the people of North Durham and my supporters who gave me the opportunity to serve them.”