Britain's former Prime Minister David Cameron resigned his seat in the House of Commons on Monday, September 12, less than three months after losing an EU referendum in which he had campaigned to stay in the bloc, AFP reports.

Cameron stepped down as Prime Minister in June, hours after Britain's dramatic vote to leave the European Union (EU), handing power to his successor Theresa May in July.

"The circumstances of my resignation as prime minister and the realities of modern politics make it very difficult to continue (in parliament)... without the risk of becoming a diversion," Cameron said in a statement.

"I fully support Theresa May and have every confidence that Britain will thrive under her strong leadership," the 49-year-old added.

The former premier was pilloried after the shock referendum defeat.

Critics accused him of recklessness in holding the vote in the first place and mismanaging the Remain campaign in the face of anti-EU populism, AFP says.

His decision to stage the referendum was seen in Westminster as a bid to placate eurosceptic opponents in the centre-right Conservative Party.

His resignation from parliament is unusually quick -- former prime ministers have typically retained their seats for a number of years after leaving office.