George Osborne is to step down as an MP to focus on his new role as editor of the London Evening Standard.
In a letter to his constituents in Tatton in Cheshire, the former chancellor said he was "very excited" about the prospect of editing the paper.
However, he hinted at a possible future political comeback, saying he was leaving Parliament "for now".
In his letter, published in the Standard, Mr Osborne said he intended to continue to take an active role in debating the future of the UK.
"I am stepping down from the House of Commons - for now. But I will remain active in the debate about our country's future and on the issues I care about, like the success of the Northern Powerhouse," he said.
"I want a Britain that is free, open, diverse and works with other nations to defend our democratic values in the world.
"I will go on fighting for that Britain I love from the editor's chair of a great newspaper. It's still too early to be writing my memoirs."