Government Chief Whip Andrew Mitchell has resigned after swearing at police guarding Downing Street.
Last month as Mr Mitchell tried to leave Downing Street he was told the gates could not be opened for his bicycle and he would have to use an alternative exit.
He reacted angrily to the police officers and reports claimed he called them, 'plebs' and morons and swore at them.
ITV News Political Correspondent Romily Weeks reports:
In his letter of resignation Mr Mitchell denied using the terms 'plebs' or morons but admitted that his parting shot, "I thought you guys were supposed to f***ing help us," was unacceptable.
He has already apologised to the officers concerned.
I did not, never have and never would call a police officer a "pleb" or a "moron" or use any of the other pejorative descriptions attributed to me.The offending comments and the reason for my apology to the police was my parting remark "I thought you guys were supposed to f**king help us".It was obviously very wrong of me to use such bad language and I am very sorry about it and grateful to the police officer for accepting my apology.
Since the original incident last month the Tory enforcer, who only became the Chief Whip in the last Cabinet re-shuffle, has faced increasing pressure to step down.
During Prime Minister's Questions this week Labour leader Ed Miliband claimed Mr Mitchell, "was toast," despite David Cameron attempting to draw a line under the affair:
MPs on both sides of the Chamber hailed Mr Mitchell's resignation. With Conservative MP Stephen Mosley saying he had done the right things for the party:
John Woodcock is shadow transport minister:
He has been replaced as Chief Whip by Sir George Young.