T-shirts sold to raise funds for Jeremy Corbyn's leadership campaign are being made by Bangladeshi workers paid just 30p an hour, it has been reported.
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.
Momentum said it had cancelled the contract for the T-shirts suggesting that it may have been misled by one of its suppliers in relation to labour practices at the factory.
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.
The move has been taken after allegations surfaced that Momentum and one of its suppliers may have been misled by a third party supplier in relation to its labour practices.
The group said it would draw up a code of practice capable of maintaining confidence, in spite of the complexity of modern supply chains, that all campaign materials have been produced by businesses that respect labour rights and human rights.
A spokesman said: "Momentum is dedicated to championing people's rights at work both at home and overseas.
"We want every worker at home and abroad to be in a trade union, and to enjoy the full protections that the ILO (International Labour Organisation) recommends as minimum standards. We refuse to work with any supplier who does not uphold these standards."
The Mail on Sunday reported that the basic salary at the factory in Baipayl, near the capital Dhaka, was around £63 a month - well below the average wage in Bangladesh of £93.
Employees were said to live in shanty towns made of corrugated iron sheets by a polluted river with several family members sleeping together in cramped rooms.