UNION activists have staged a musical flashmob outside a Glasgow bar run by millionaire owner Stefan King, highlighting his mistreatment of zero-hours contract workers.

Campaigners from Better Than Zero, a Scottish Trades Union Congress (STUC) initiative, sang out for fair pay and conditions in a performance outside the G1 Group venue on Thursday night.

The chorus of dozens of campaigners assembled outside The Lane bar in Ashton Lane to sing a rendition of “I Need a Dollar” by Aloe Blacc.

Others stood on a balcony above them to unfurl a big banner which read: “G1 = profit; 2,895 staff = no minimum wage,” while customers enjoyed the show and passers-by stopped and watched.

Managers at The Lane called the police on the activists, but officers arrived on horseback long after most of the singers had left.

Cat Boyd, one of the organisers, said that she was inspired to help set up the stunt after hearing “countless horrific stories” from disenfranchised G1 Group workers.

Cases included undercutting wages, health and safety being openly flouted, widespread use of zero-hours contracts and stories of some people working for 15 hours straight with no breaks, she said.

“Better Than Zero is about sending the message to employers that think they’re beyond reproach to give them a wee reality check. People are fed up being treated like they’re nothing,” she said.

“The ones we’ve spoken to are stuck in precarious work and don’t have a lot of choices, and they’re angry.

“We’re helping them express that anger in proactive way. The cases we’ve heard — that are quite phenomenal — need to stop.

“We will keep doing the stunts, and it will escalate, until it gets better.”

HMRC announced earlier this year that Mr King had failed to pay the national minimum wage to nearly 3,000 of his employees as part of a name-and-shame drive, ranking him the worst of 48 employers cited.

The Daily Record reported in March that Mr King owed a total of £45,124 to his workers.

Employers who fail to pay the minimum would have to pay the arrears at current rates as well as a fine of up to £20,000 and in the most serious cases, offenders can be prosecuted.