The row began when the Labour LGBT group posted the following message on social media platform Twitter: "Manager at The Greencoat Boy near Westminster told members he would have refused the #LGBTLabour booking if he’d known it was an LGBT group!".
The alleged comments sparked a visit from the police, who were photographed interviewing members of the group inside the pub.
Sarah Brown posted the following message on Twitter: "very sad to hear that the Greencoat Boy shown as homophobic in taking LGBT booking – but good to see so many are concerned here."
Former deputy prime minister John Prescott Tweeted: "40 years ago we campaigned against a Hull pub that banned 'women & queers' This is disgraceful. Fully back you #greencoatboy "
The #greencoatboy and #bullybar hastags are currently among the most Tweeted on the social media platform.
Ed Balls, a candidate for the leadership of the Labour Party described the alleged incident as "really shocking" and Labour MEP Michael Cashman has led calls for a boycott of Punch Taverns who own the pub. A boycott campaign organised on Facebook has already signed up almost 500 supporters.
Punch Taverns have not yet responded to a request for a comment from PinkNews.co.uk.
Source: Pink News