David Cameron has quit as a Conservative MP, just months after the UK voted to leave the EU and he resigned as prime minister. Cameron's decision to quit the House of Commons means he has triggered a by-election for the Oxfordshire seat of Witney.

"Having fully considered my position over the summer, I have decided that I am going to stand down as the Member of Parliament for Witney. There will now be a by-election and I will do everything that I can to help the Conservative candidate win that election," he said.

"In my view, the circumstances of my resignation as Prime Minister and the realities of modern politics make it very difficult to continue on the backbenches without the risk of becoming a diversion to the important decisions that lie ahead for my successor in Downing Street and the government.

"I fully support Theresa May and have every confidence that Britain will thrive under her strong leadership."

He is expected to concentrate on finishing a memoir for publication next year and join the lecture circuit. The Times reported that as well as free schools, he will focus his efforts on international aid and tackling corruption.

The 49-year-old first entered parliament in 2001 after working as a special adviser and a brief spell as PR man for Carlton Communication.

He later beat now Brexit Secretary David Davis to become Conservative Party leader in 2005 before leading his party to power at the 2010 general election by forming a coalition government with the Liberal Democrats.

Cameron beat expectations to secure a majority at the 2015 general election by slightly increasing his party's share of the vote and securing 24 more seats. Theresa May, the former Home Secretary, succeeded Cameron as Conservative leader and prime minister in July.

Witney 2015 election result

Cameron's full statement

"I spoke this morning to the chairman of the West Oxfordshire Conservative Association and I have just come from a meeting with my constituency agent and other members of staff.

"Having fully considered my position over the summer, I have decided that I am going to stand down as the Member of Parliament for Witney.

"There will now be a by-election and I will do everything that I can to help the Conservative candidate win that election.

"In my view, the circumstances of my resignation as prime minister and the realities of modern politics make it very difficult to continue on the backbenches without the risk of becoming a diversion to the important decisions that lie ahead for my successor in Downing Street and the Government.

"I fully support Theresa May and have every confidence that Britain will thrive under her strong leadership.

"It has been an honour to serve the people of Witney and West Oxfordshire for the last 15 years. I want to thank them for making the job of representing them such a pleasure and a privilege.

"I would like to thank the party workers, volunteers, councillors and supporters for all they have done to help me.

"Our house in Dean is the place Samantha, my children and I call home, and that will not change. I will continue to support the local causes and charities that mean so much to me and many others in this beautiful and enterprising part of our country.

"I now look forward to a life outside of Westminster, but hope to continue to play a part in public service and to make a real and useful contribution to the country I love."