Tory MP Andrew Bridgen was arrested over a “drunken sex attack” on political aide.

The married father-of-two is accused of sexually groping a 29-year-old political aide at a Westminster pub after a marathon drinking session.

It is unconfirmed whether or not Bridgen, 46, and his accuser had known each other previously, but the pair were seen drinking with a second man on Wednesday evening and staff at the pub confirmed that the MP left with the aide.

The trio later went to Bridgen’s Westminster flat for further drinks and it was there, early yesterday, the incident is alleged to have taken place.

It is understood a neighbour or member of staff at the apartment block called police after the woman tearfully asked for help.

Bridgen, the MP for North West Leicestershire who was first elected to parliament last year, is a former officer in the Royal Marines who has praised Government efforts to combat violence against women.

He was arrested at around 2am and taken to a central London police station.

Strenuously denying any wrongdoing, he was finger-printed, asked to provide a DNA sample and pose for a police mug-shot. Police released him on bail until next month, pending further inquiries.

Last night, however, there were claims in Westminster that the accuser, who was interviewed by sex crimes detectives, might withdraw her allegations.

Sources in Westminster also said that Bridgen was separated from his wife, Jackie, 33, whom he wed in 2000. They have two sons together, Alexander and Benjamin.

Jackie, a Conservative councillor, was last night seen returning  to the family home in a gated estate in Coleorton, Leicestershire. She drove a black Range Rover Sport towing a horse box with a brown horse inside.

She refused to make any comment.

Graham Allman, the chairman of the North West Leicestershire Conservative Association, said: “My first concern is with Jackie and the family.

“I spoke to Mr Allman this morning and offered him the support of myself and my family.

“He said he’d just see how things would unfold.

“He’s a good family man. I’ve known him a long time. He’s an all-round good guy.

“He’s good for the constituency, a very popular man.’

Bridgen has earned a reputation in Westminster as a Eurosceptic Right-winger and on his website, he has praised action the Government has taken to support women and families, in particular  “tackling violence against women and girls”.

Born in Burton upon Trent, Staffordshire, he graduated from Nottingham University with a degree in biological sciences. He trained as an officer in the Royal Marines, returning home at 23 to help with the family market gardening business, which now specialises in producing pre-washed potatoes.

One local said last night: “He’s known as the Potato Baron round here. He employs 200-odd people. It’s rough finding work at the moment so people are grateful for the work he provides.”

Bridgen joked about the length of women’s skirts in his maiden speech in the House of Commons last June.

He told MPs: “I took advice on what the contents of a maiden speech should be, and I was surprised by some of what I heard.

“I was told that my speech should have all the attributes of a lady’s well-cut dress, meaning that it should be long enough to cover all the important points but still short enough to be interesting.”

A Scotland Yard spokesman said: “A 46-year-old man has been arrested on suspicion of sexual assault against a 29-year-old woman at an address in SW1 in the early hours of Thursday June 9. He has been bailed to return on a date in mid-July.”