In a resignation letter issued on Thursday Mike Amesbury said he wanted to have more freedom to campaign in his local constituency.
The MP, who last week expressed sympathy for workers going on strike, also said he wanted to “stand shoulder to shoulder with all whose only ask is a fair deal for them and their families”.
He added: “I intend to provide this support and voice from the backbenches.”
Last week the Weaver Vale MP skirted a ban by Sir Keir on frontbenchers supporting rail strikes, commenting that “workers do not withdraw their labour lightly” and adding: “They are fighting to save jobs in this cost of living crisis.”
The Labour leadership’s order to his team not to attend pickets caused private consternation amongst some of his frontbenchers, especially after polls showed broad public support for the industrial action and its aims.
But Mr Amesbury said he was proud of what Labour was achieving and hoped Sir Keir would become prime minister, with “a purpose” and “a bold offer”.
“Our recent success in Wakefield building upon good local election results in England, Scotland and Wales puts us well and truly back on the pitch. I will do all I can to work with the Labour movement to secure a Labour victory and put you in 10 Downing Street,” he said.
“This must be a victory with a purpose, a mission to drive out inequality in Britain with a bold offer that gives hope, powers up people and our communities.”
He added: “I secured my marginal seat from the Tories in 2017 and retained it in very challenging circumstances in 2019. At both elections I promised that I would put my constituents first. I believe that if I am to continue to do so, I am not able to give the role of Shadow Local Government Minister the energy it demands and deserves.”
Mr Amesbury has been shadow minister for local government since 2021 and was previously shadow minister for employment.
Lisa Nandy, who leads the shadow local government team, said it had been “an absolute pleasure to work with” Mr Amsbury, adding: “Your constituents are lucky to have you.”