Britain's former prime minister David Cameron on Monday resigned his seat in the House of Commons, nearly three months after losing an EU referendum in which he had campaigned to stay in the bloc.
Cameron stepped down as prime minister in June, hours after Britain voted to leave the European Union, and handed over the reins of power to his successor Theresa May in July.
"In my view, the circumstances of my resignation as prime minister and the realities of modern politics make it very difficult to continue (as a member of parliament)... without the risk of becoming a diversion," Cameron said in a statement Monday.
"I fully support Theresa May and have every confidence that Britain will thrive under her strong leadership," the 49-year-old said, adding: "I now look forward to a life outside Westminster".
The former premier has faced sharp criticism in the wake of his surprise referendum defeat from critics who accused him of recklessness in holding it in the first place.
Cameron announced his intention to hold the vote in 2013 in what was seen at Westminster as an attempt to placate eurosceptic opponents in the centre-right Conservative party.
His resignation from parliament less than three months after stepping down is unusually quick. Former prime ministers have typically retained their seats for a number of years after leaving office.
Cameron, had been MP for Witney in the rural county of Oxfordshire, northwest of London, since 2001.
He said he would continue to live there.
At the time of his resignation as prime minister, he insisted he was "keen to continue" as a constituency MP and intended to seek re-election at the next general election, due in 2020.
Cameron is not known to have taken on any other roles since stepping down. His media appearances since have been in pictures of him holidaying with his family.
"Obviously I'm going to have to start to build a life outside Westminster," he was quoted as saying by ITV in an interview.
"I'm only 49 and I hope I can still contribute in terms of public service and contribute to our country," he said.
His decision was welcomed by allies.
Former foreign secretary William Hague wrote on Twitter: "Right decision by David Cameron to leave Commons - former Prime Ministers are either accused of doing too little or being a distraction."
Cameron's decision to quit will trigger an obscure parliamentary procedure, because lawmakers are technically not able to resign.
Cameron will be named as either the Crown Steward and Bailiff of the Chiltern Hundreds or the Crown Steward and Bailiff of the Manor of Northstead and a by-election to pick his successor will be held.