A prominent Labour activist has revealed she was raped at a party event and then told not to report it by a senior member of staff because it might “damage” her.

Bex Bailey, who eventually won a seat on the Labour’s ruling National Executive Committee, said she did not receive the support she needed adding that she was not even “given a cup of tea” when she tried to raise the alarm in 2011.

It comes amid a series of claims about sexual harassment and abuse in British politics, with another woman telling how she fled a hotel room after an MP physically forced her onto a bed.

A spreadsheet compiled by parliamentary office workers containing the names of 40 Conservative MPs, including ministers, was circulated in Westminster setting out allegations of inappropriate behaviour.

Speaking to BBC Radio 4’s PM show, Ms Bailey said that the attack on her when she was 19 years old was not carried out by a Labour MP, but was committed by someone more senior to her in the party.

She said: “I was seriously sexually assaulted at a Labour party event by – it wasn’t an MP – but someone who was more senior to me.

“It took me a while to summon up the courage to tell anyone in the party, but when I did, I told a senior member of staff who told me...it was suggested to me that I not report it.

“I was told that if I did it might damage me.”

Asked later in the interview how serious the assault was, she said: “I was raped.”

Ms Bailey said that she had not reported the attack to the police at the time because she felt “scared” and “ashamed”, and because she feared being the centre of gossip and people not believing her.

She explained that she was now fighting for changes to how political parties deal with such reports, because she had not received the support she needed when she first reported the incident.

Woman who worked for MP reported sexual assault four times but was 'ignored by Parliament authorities'

She went on: “I wasn’t given good advice. I wasn’t given a procedure when I asked for it so that I could see what would happen if I did report it and then make a decision.

“It seemed to be that there wasn’t one that existed and I wasn’t signposted to anyone else that could help me in terms of a charity or anything like that.

“I don’t think I was even given a cup of tea at the time. It was quite a horrible experience.”

Former Labour leader Ed Miliband said he was shocked by the allegations and praised Ms Bailey’s “courage and bravery” in a tweet.

Labour has said the party’s general secretary Iain McNicol will appoint an independent legal expert to investigate the allegations, with details made public at the earliest possible opportunity.

A Labour spokesperson said: “The Labour Party takes these allegations extremely seriously. It takes great courage for victims of rape to come forward – and all support must and will be made available to them.

“We would strongly recommend that the police investigate the allegations of criminal actions that Bex Bailey has made.

“Labour will also launch an independent investigation into claims that a party employee acted improperly over these 2011 allegations.”

Jeremy Corbyn has ordered an inquiry into the allegations (PA)

But Ms Bailey said she wanted to see an independent agency set up so that incidents can be reported with victims dealt with fairly and without political bias.

She added: “I think that we will have the confidence to raise these issues if the procedure is improved.

“It’s fantastic that [Jeremy Corbyn is] taking this forward and has been quite strong on it, and I really hope that we’ll see some change and I’d love to work with them on that.”

But minutes after her story was aired, another woman told how an MP sexually assaulted her, forcibly holding her on a bed in a hotel room while on a business trip to Europe with parliamentary colleagues.

Bex Bailey speaks at a Labour Party conference in 2014 (Rex)

The woman said she had found herself alone with the MP in a hotel bar after other members of her delegation went to pack their bags before a flight home.

She said: “He said, ‘come and talk to me while I pack my bag,’ and I honestly didn’t think anything of it. I thought we had a very professional relationship. There had been no indication of any flirting or anything at all.

“But when I got to his hotel room he said, ‘come and sit on the bed’, which made me feel uncomfortable, so I didn’t and I was standing near the door. But he was quite insistent, so tried to brush it off, saying, ‘come on pack your bags and we’ll go and meet everybody’.

Theresa May wants new parliamentary systems to help victims of sexual abuse (EPA)

“At which point, he basically pulled me on to the bed and pushed me back, and tried to kiss me. I very clearly said, ‘no, this is not what I want.’ He held me by my shoulders and pushed me back again. On the third time, I managed to push him off again and basically ran out the room. Initially I was just really shocked and I didn’t expect it but I was quite quickly scared because I knew I was in a vulnerable situation.”

The Independent reported on Monday how the woman had tried to report the assault four times but that her claims had not been taken seriously by the authorities.

Among those named in the dossier being circulated in Westminster are a cabinet minister and a former cabinet colleague accused of paying women to be silent about incidents.

Andrea Leadsom and Harriet Harman respond to sexual harassment claims in House of Commons

Portions of the so-called “dirty dossier” have already been published in the mainstream media with varying amounts of information redacted, but neither the fact it has come from within the Conservative Party, nor the allegations contained within have yet been confirmed.

In total, 25 Tory MPs are named as having allegedly behaved inappropriately, mainly with staff. A video is said to exist of one MP who engaged in a distasteful sexual practice with three men, while another behaves inappropriately while “perpetually intoxicated”, the dossier says.

The full details of the dossier were revealed as Theresa May’s spokesman declined to say she had full confidence in Sir Michael Fallon, the Defence Secretary, after he apologised for an incident.

Jeremy Hunt says there will be an investigation into whether sex pest scandal behaviour has broken ministerial code

Sir Michael admitted putting his hand on a female journalist’s knee, but will not be investigated by the Cabinet Office, No 10 said.