Thousands of part-time council workers, including cleaners and teaching assistants, could receive money after a five-year legal battle over holiday pay.

Unison took the case on behalf of mainly women workers in Greenwich, arguing the council failed to calculate annual leave properly, leaving staff losing up to five days' pay a year.

The union brought employment tribunal claims on behalf of almost 500 term-time-only staff, saying they had been treated less favourably than other workers.

A settlement worth around £4 million has been agreed with the council, affecting 5,000 workers, Unison announced.

Councillors agreed to revise the formula used to calculate holiday pay, backdated to 2013.

Workers could now receive hundreds of pounds each, Unison said.

Assistant general secretary Christina McAnea said: "This is a victory for all low-paid women working in the public sector, what started out as just one case could soon be having an impact far beyond south-east London.

"Laws that began life in Europe have enabled Unison to restore justice and ensure that all part-time workers in the Royal Borough of Greenwich are paid the correct holiday pay for the jobs they do.

"Other employers may have made similar errors with their holiday calculations. If they have we'll be on to them to make sure all term-time staff are paid what they're due."

Cllr Chris Kirby said: “There were around 18 different formulas being used by all councils across the country. Only one of those formulas can be correct.

"We started negotiations with national unions on this two years ago and have been able to work with our partners and our staff to come up with a proposal that works for them. It’s a proposal that they are happy with and that is sustainable and doesn’t threaten frontline jobs.”