LONDON, England (AFP) - A deputy speaker in Britain's lower house of parliament quit on Tuesday after the public prosecutor announced that he will be charged with offences including rape and sexual assault.

Nigel Evans, 55, a lawmaker in Prime Minister David Cameron's Conservative Party, was initially arrested in May on suspicion of committing rape and sexual assaults between 2009 and March this year.

He was re-arrested in June over a further three counts of indecent assault, some dating back to 2002, and will now appear in court on Sept 18.

"After careful consideration, we have concluded that there is sufficient evidence and that it is in the public interest to prosecute Mr Evans," the Crown Prosecution Service said in a statement.

"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." The allegations involve men in their twenties.

Evans later announced he was leaving his role as deputy speaker, but maintained his innocence.

"Whilst I'm 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," he said after leaving Preston police station in north west England.

"Having informed my fellow deputy speakers Lindsay Hoyle and Dawn Primarolo, my association chairman and my staff, I can confirm I will now resign as deputy speaker." However, he revealed that he would remain an MP.

Lancashire Police earlier said in a statement: "A 55-year-old man from Pendleton in Lancashire has today answered his bail following his arrest in May on suspicion of rape and sexual assault and in June on suspicion of three further offences of indecent assault.

"He has subsequently today been arrested on suspicion of indecent assault and sexual touching of two further victims." At the time of the original allegations, Evans dismissed them as "completely false", saying they had been made by two people he had "regarded as friends".

In June he said: "I continue to refute all allegations." Evans was one of three deputy speakers elected in a secret ballot of lawmakers in 2010 and later that year revealed he was gay, saying he was "tired of living a lie".

The Welsh lawmaker has stepped aside from his speaker duties since his initial arrest but has continued to serve as a member of parliament.