A union representing workers in the gig economy is aiming to raise £50,000 to fund its continuing fight against Deliveroo as it battles for financial survival.

The Independent Workers Union of Great Britain, which has backed a series of employment tribunal cases pushing for a better deal for delivery couriers and cleaners, needs a cash injection as it faces a £10,000 bill for costs relating to an unsuccessful attempt to win union recognition at the food delivery firm.

In a key legal ruling, the Central Arbitration Committee, a body that resolves worker disputes, said the Deliveroo’s riders were self-employed contractors and not entitled to holiday pay or the national minimum wage because the firm had given them the right to allocate a substitute to do work for them.

It is understood that the bill from that case, made up largely of Deliveroo’s legal costs, which IWGB may have to cover after losing, puts the union in a tenuous financial position. The IWGB also wants to fund a high court challenge to a ruling against the union seeking a judicial review of the CAC decision, slated for 12 June.

The union has turned to Crowdjustice, which has previously been used to raise funds for legal action against council budget cuts and to challenge European states’ lack of action on climate change.

Jason Moyer-Lee, the general secretary of the IWGB, said: “In a world where the government does nothing to end exploitation in the so-called ‘gig economy’, the onus falls entirely on workers and their unions. Justice should not be reserved for those with the deepest pockets.”

At the time of the CAC ruling, Dan Warne, the managing director for Deliveroo in the UK and Ireland, described it aa “a victory for all riders who have continuously told us that flexibility is what they value most about working with Deliveroo”.Since then the food delivery firm has committed to giving riders free insurance to protect earnings if they are involved in an accident.