Deputy Speaker Nigel Evans has been charged with eight sexual offences against seven different men
Evans, one of Speaker John Bercow's three deputies, has been charged with two counts of indecent assault, five counts of sexual assault and one count of rape.
The alleged offences took place between 2002 and 2013. He has resigned as Deputy Speaker but will continue as the Conservative MP for Ribble Valley.
The director of public prosecutions, Keir Starmer QC, said tonight: "Following an investigation by Lancashire police, the Crown Prosecution Service has received a file of evidence in the case of Mr Nigel Evans MP which concerns allegations of a sexual nature."
"After careful consideration, we have concluded that there is sufficient evidence and that it is in the public interest to prosecute Mr Evans. Lancashire Constabulary has therefore been authorised to charge two counts of indecent assault, five counts of sexual assault and one count of rape relating to a total of seven alleged victims."
All the charges relate to men in their 20s.
Evans, who is a member of Politics.co.uk's editorial board, has previously denied the allegations, describing them as "completely false".
"May I reassure everyone at this time I will robustly defend my innocence," Evans said in a statement last night.
"I have today answered bail following complaints I have said were incredulous. Whilst I am saddened this case has not been closed today, I am certain of two things: firstly that I am innocent; and secondly that my innocence will be demonstrated.
"Having informed my fellow deputy Speakers... my association chairman and my staff, I can confirm I will now resign as deputy Speaker.
"However, I will continue to work hard for the people of the Ribble Valley from the backbenches where I first started my political career in 1992."
Evans will appear before Preston magistrates court later this month.