A Jeremy Corbyn campaign group has cancelled a contract with its merchandise supplier over claims T-shirts were made by Bangladeshi workers earning just 30p an hour, reports The Mirror.Momentum, a campaign group set up to support the UK opposition leader Jeremy Corbyn’s leadership, sells T-shirts for £10 at rallies and through their website.One design features Jeremy Corbyn’s name written in the style of the classic Superman logo.But the Mail on Sunday said that it had found machinists living in poverty-stricken conditions were required to work 10 hours-a-day to make the garments which were sold for £10 each by the Momentum campaign group.However The Mail on Sunday said the factory concerned was owned by the same firm which was revealed by the newspaper to have paid factory workers in Nicaragua and Haiti as little as 49p an hour to make the official Team Corbyn T-shirts for his first Labour leadership bid.Momentum said it wanted to ensure a zero-tolerance policy on unethical practices anywhere in the supply chain and would be seeking a new supplier with full ethical standards.