Tracy Brabin, who replaced Jo Cox as MP after her murder, became the target of criticism after one user shared a picture of her wearing the off-the-shoulder dress in the Commons.
The image of Ms Brabin, an ex-TV actress, was featured in a tweet that said: "Is this really appropriate attire for parliament? #DressStandards."
Below the man's post was met with dozens of replies from users, including one which read: "Looks like she was banged over the wheelie bin at the back of the pub last night."
Another tweet came from Brexit Party Candidate, Deneice Florence-Jukes, who wrote: "Trying to work out if @TracyBrabin is on her way out or on her way back from clubbing! How have parliamentary standards fallen so low?"
Ms Florence-Jukes claims in her Twitter bio to have served in the Royal Air Force and the Metropolitan Police.
Others attempted to demean her using her former career as an actress, when she found fame appearing in a number of popular TV shows including Coronation Street.
Ms Brabin, the shadow culture secretary, replied to the tweet: “Sorry I don’t have time to reply to all of you commenting on this but I can confirm I’m not….
“A slag, Hungover, A tart, About to breastfeed, A slapper, Drunk, Just been banged over a wheelie bin.
“Who knew people could get so emotional over a shoulder…”
At the time of wearing the dress, Ms Brabin was raising a point of order in the Commons on the Government's decision to order senior journalists from some of the UK’s major news organisations to leave before a briefing on Boris Johnson’s Brexit plans.
