Profile: Andrew Mitchell
Chief Whip Andrew Mitchell has resigned over a row with police at the gates of Downing Street.
It follows weeks of speculation about his future with Labour, the Police Federation and the Daily Telegraph all calling for him to go.
Mr Mitchell was appointed chief whip in David Cameron's first major reshuffle in September, leaving his post at international development.
Within a couple of weeks, after what he called a "long and extremely frustrating day", he swore at a police officer who stopped him cycling out of the main Downing Street gates.
He apologised for the incident, saying he was sorry he had not shown the police enough respect, but denied reports he had called the officers "plebs".
Despite getting backing from the prime minister, his apology failed to end the row about the incident, with police officers protesting outside Mr Mitchell's constituency office wearing T-shirt with the words "PC Pleb and Proud" printed on them.
In an attempt to defuse the situation, Mr Mitchell stayed away from the Conservative Party conference, being held in Birmingham close to his Sutton Coldfield constituency.
However, speculation about his future continued and, following a meeting with representatives from the West Midlands Police Federation, Mr Mitchell decided it was time to resign.
It brings to an end his ministerial career, which began as a junior whip in the early nineties.Maastricht rebellion
Mr Mitchell, 56, was first elected in 1987, having grown up in a political household - his MP father Sir David Mitchell served as a minister under Margaret Thatcher.
He was educated at Rugby public school. It is here the self confessed "stern disciplinarian" is said to have earned the nickname "Thrasher".
He read history at Jesus College, Cambridge where his extra curricular activities included chairing the student Conservatives and becoming President of the Cambridge Union.
Before going to university, Mr Mitchell served in the Royal Tank Regiment and as a UN peacekeeper in Cyprus.
But upon graduating he moved into the world of banking, taking up a role with investment bank Lazard Brothers.
During this time he got married to Sharon, a doctor. They have two daughters.
Andrew Mitchell biography
- He is 56 years old and married to a doctor. They have two daughters.
- His father was a Conservative politician and minister under Margaret Thatcher
- He is a former soldier who served as a UN peacekeeper in Cyprus in the 1970s
- He entered Parliament in 1987 and was a whip during the Major government
- He lost his seat in 1997 but returned to Parliament four years later
- While an opposition spokesman on international development, he was also a director of a merchant bank
- He was appointed international development secretary in 2010 and became Tory chief whip earlier this month
He was determined to get into politics and, having failed to get elected in 1983 in Sunderland South, he won the seat of Gedling in Nottinghamshire in 1987.
Here he started his career in the whip's office, serving as a government whip during the notorious rebellion over the Maastricht Treaty - where a number of Conservative MPs voted against Prime Minister John Major.
He was made a vice-chair of the Conservative Party and later promoted to be social security minister, and he was tipped as a future chief whip in the mid-1990s.
But his career suffered a set back when he lost his seat in the Labour landslide of 1997.
This brought to an end a decade of serving in the House of Commons alongside his father - who retired the same year.
He returned to Lazard Brothers as a director and began his search for a new, and hopefully safer, seat.
After five other attempts, he beat a large field to succeed Sir Norman Fowler in Sutton Coldfield, where he has built up a large majority since 2001.
Back inside the Commons, he got involved with the party's leadership machinations as it tried to find someone to take on Tony Blair.
As early as October 2002 he was named by the Daily Telegraph as one of four ringleaders in a plot to oust then leader Iain Duncan Smith.Police row
He found favour with Mr Duncan Smith's replacement, Michael Howard, who promoted him into the shadow cabinet as shadow international development secretary after the 2005 general election.
He ran David Davis's failed leadership campaign in 2005, but kept his shadow cabinet job under David Cameron's regime. He is now seen as a Cameron loyalist.
Mr Mitchell stayed in the shadow international development role all the way through to the 2010 general election, after which he took the post on in government.
He oversaw moves to make aid more transparent and repeatedly pledged to enshrine in law an obligation for the UK to spend 0.7% of its national income on overseas aid - something which has angered some of his Conservative colleagues.
When David Cameron carried out his first major reshuffle in early September, he made Mr Mitchell his new chief whip. It was to be a short-lived appointment, lasting just over a month.
His friend of 25 years, MP Michael Brown - who worked with Mr Mitchell in the whips office in the early 90s - said the incident with Downing Street police was "totally and utterly out of character".
He said: "A 30 second moment of madness by the chief whip, who I know to be a very decent and honourable man.
"I come from the wrong side of the tracks. I'm a secondary modern school boy, an eleven plus failure and I can tell you working with Andrew Mitchell was an absolute delight and a privilege."