Rishi Sunak’s government has suffered another blow after his energy minister announced he was quitting.
Graham Stuart said he would “fully support” the prime minister from the back benches but wanted to focus on local issues instead.
He is the third senior minister to quit in recent weeks as the Tories face the prospect of a disastrous general election defeat.
His announcement comes a month after former armed forces minister James Heappey announced he was leaving government and standing down as an MP at the election.
Education minister Robert Halfon also resigned and will not stand again, while Ben Wallace quit as defence secretary last year.
Liberal Democrat deputy leader Daisy Cooper said the drumbeat of Conservative resignations was becoming “deafening” as ministers find “any excuse they can to get away from this deeply unpopular Conservative government”.
Mr Stuart is the MP for Beverley and Holderness in Yorkshire, where he has a majority of more than 20,000.
But Labour overturned a similar majority in what was considered a Tory stronghold in Selby and Ainsty last year.
Mr Stuart said he will turn his focus to issues such as making roads safer, broadband delivery and increasing the number of defibrillators in his constituency.
He said: “I’m proud to have served in the government for most of the past eight years, but now it’s time to focus on Beverley and Holderness.
“I’m proud to have achieved much over the past 18 years, from rock armour at Withernsea to saving East Riding Community Hospital, installing life-saving defibrillators in rural communities, and slashing fares on the Humber Bridge.
“I’m looking forward to working with communities to make our roads safer, helping the council take full advantage of the opportunities brought by devolution, pressing the case for York to Hull Rail, and improving healthcare in Beverley and Holderness.”
In addition to his role as energy and net zero minister, Mr Stuart also served in the Foreign Office, the Department for International Trade, and as an assistant whip to the Treasury.