The controversial decision - which would come as a shock to the likes of Debbie Harry, Tina Turner, Stevie Nicks, Chrissie Hynde and Gwen Stefani - came to light when an up and coming band had its gigs cancelled.

Singer Hannah Sowerby asked why and was told by bosses at Dr Brown’s rock bar in Middlesbrough that regulars do not like female vocalists.

Hannah, 23, singer with both Revenant and Syndicate 66, said: “I haven’t been allowed to play there because I’m female, despite the fact my band can draw a good crowd.

“You would never get people saying they don’t like male bands, because not all male singers are the same – just like not all female singers are the same.

“It is a sexist attitude from the regulars and there’s no excuse for it in 2017, you’d think we’d be past this kind of thing by now.”

Landlady Paula Rees denied the rule was sexist but admitted she was not the best judge as she preferred opera.

She said: “We had female singers on in the past and customers just didn’t like it - we’re a rock bar and they don’t think that women should sing male rock songs.

“It’s nothing to do with me, it’s the pub’s regulars who come in every week, they won’t come in if there’s a female singer.”

Ms Rees admitted they might consider relaxing the ban if bands could guarantee large crowds but said as a general rule it would remain.

She added: “We have got to keep our regulars happy, I’m not a rock fan so I can’t judge myself but I’ve been told that some women can sing and some can’t, but they can’t sing heavy rock.

“If we put a poster up and our regulars know there’s a woman in the band, they won’t give them a chance - they’re my bread and butter and we can’t risk nobody coming in.”

A spokesman for the Equalities and Human Rights Commission said that the pub’s ban was not illegal but listed a number of female-fronted acts as he claimed some of the most successful musicians in the world were women.

A spokeswoman for the Musicians’ Union said: “We have not been involved in this particular incident but we take discrimination on any grounds very seriously.

“For the purposes of booking shows, female-fronted bands should not be treated any differently to male-fronted bands, and neither should they be expected to identify themselves or their music according to their gender.

“We have been investigating the seeming lack of female artists on festival line-ups but this is the first time I’ve personally come across a booking cancelled explicitly because of the gender of the performer and the assertion made that audiences aren’t interested in gigs featuring women.

Dr Brown’s regulars are mainly middle aged male bikers and leather jacketed rockers.

At the bar yesterday drinker Trev Ronald, 44, said: “Girls don’t sound right if they’re singing Dio or Ozzie Osbourne. 

“You can’t do War Pigs by Sabbath with a female vocal, it’s not right.

“If they can’t do it they should stick to karaoke.”