Labour MP Paul Sweeney has publicly claimed that he was sexually assaulted by aTory MP in a Commons bar last year.

Mr Sweeney alleges that Ross Thomson groped him last October, and has since branded the investigation by Westminster's standards watchdog a 'shambles'.

The Glasgow North East MP told the Scottish Mail on Sunday he was left feeling 'mortified' after the alleged assault.

Aberdeen South MP Mr Thomson released a statement on Twitter on Sunday morning in response to the allegation, in which he denied any wrongdoing.

Mr Sweeney claims Thomson 'drunkenly' intruded on a conversation he was having with friends before the Tory MP pressed his hand down the front of his trousers.

"I felt paralysed. It was just such a shocking thing. I was in a cold sweat, it was mortifying," the Labour MP said. "Nobody knew where to look at the table. It’s embarrassing.

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"In the back of my mind, I was thinking that if I just punched the guy, who knows where that could end up when there’s a bar full of journalists.

"I couldn’t fight, so I took flight."

He said he then went to sit with other MPs, when Thomson followed him across the room and continued to touch him.

"I sat on this for ages because I didn’t want to make a fuss out of it," Mr Sweeney continued. "But when I go into the chamber and he’s there doing a speech, it’s still there – that intimidation.

"He knows, and I know, what went on there. I can’t get away from him. The House of Commons is 650 MPs in a very confined environment – it’s not like you can just not see the person.

Speaking on Twitter, Mr Thomson said Mr Sweeney's allegations were "politically motivated smears".

He said: "This is the second time Mr Sweeney has gone to a national newspaper with allegations against me.

"I categorically denied the same allegations when they were first made back in March, and I continue to (do) so.

READ MORE: Aberdeen MP Ross Thomson is no stranger to controversy

"I believe every report of harassment deserves to be treated with the utmost seriousness, which is why I have complied fully with a parliamentary standards investigation.

"I think it is telling that Mr Sweeney has chosen this moment, just days out from the beginning of a general election campaign, to abandon the confidential investigation process and take his smear campaign to the Mail on Sunday.

"Mr Sweeney is weaponising an extremely serious issue and showing contempt for the people and processes that have been put in place to help deal with genuine bullying and harassment claims."

He said that the experience of dealing with the accusations had been "nothing short of traumatic".

A Scottish Conservative Party spokesman said: ‘We await the outcome of the Parliamentary Standards Commission investigation.’