Former Prime Minister David Cameron is to step down as an MP.
Cameron has represented the Oxfordshire seat of Witney since 2001, and served as Prime Minister from 2010 up to this Summer, when he was replaced by Theresa May.
Cameron informed May of his decision to step down earlier this afternoon, and told ITV News that he had thought "long and hard" about the decision.
"In my view, with modern politics, with the circumstances of my resignation it isn’t really possible to be a proper backbench MP as a former prime minister," Cameron said.
"I think everything you do will become a big distraction and a big diversion from what the government needs to do for our country."
The decision means the Conservatives will have to contest a by-election for the Witney seat, which they have held since its creation in 1983.
The decision to step down with immediate effect brings to a rapid end Cameron's career in parliament, which saw him rapidly ascend to lead his party just over four years after first being elected.
A protege of his predecessor as Conservative leader, Michael Howard, Cameron took on the leadership following Tony Blair's third electoral victory in 2005, ultimately leading the Tories into a coalition government with the Liberal Democrats at the next election in 2010.
He then delivered the Conservatives a majority government for the first time in more than 20 years, before this year's Brexit referendum proved his downfall.
Cameron resigned as Prime Minister in the immediate aftermath of the UK's decision to leave the EU, having led the Remain campaign to a narrow defeat in the June vote.