Up to 100,000 Australians could be eligible to take part in a class action against fast food giant KFC.

On Thursday, Gordon Legal launched a lawsuit against the chain, alleging it failed to provide paid rest breaks to staff over a period of six years.

Anyone employed at KFC from October 25, 2017, until now may be able to take part in legal proceedings.

More than 40,000 people currently work for the chain and tens of thousands of past employees could be eligible to take part in legal action, according to Gordon Legal.

“KFC took advantage of individuals who are often at the start of their careers, and they either don’t know their entitlements or are afraid to speak out,” Gordon Legal partner Andrew Grech said.

If successful, the firm says total claims could add up to tens of millions of dollars.

Representative applicants Neel Kashap and Roshanpal Singh were disappointed by the situation.

“We were both young and inexperienced when we started at KFC and feel disappointed that our inexperience was taken advantage of,” they said in a statement.

Shine Lawyers announced an investigation into the same issue on Tuesday, with the intention of launching a class action in the future.

They probed the issue with the Retail and Fast-Food Workers Union, claiming 90 per cent of impacted workers were likely to have been under 24.

Joint Head of Class Actions Vicky Antzoulatos said many would not have had the confidence or knowledge to speak up.

“Many of these workers were just kids facing tough working conditions,” Ms Antzoulatos said.

Gordon Legal is running its class actions on a no win, no fee basis meaning legal costs will only be charged if a settlement is awarded.

Kentucky Fried Chicken said the company had only just become aware of the claims from Gordon Legal and would respond in due course.

“We have always taken and will continue to take our legal obligations as a franchisor seriously,” the company said.

– AAP