EMPLOYERS using zero hours contracts should immediately review them amid growing concerns about their controversial terms and conditions.

That is the warning from Dorset law firm Coles Miller, which says the “social tide is turning” against the contracts.

There are 582,935 employees in the UK on zero hours contracts – treble the number in 2010, according to the Office for National Statistics. But the union Unite, drawing on research by the Chartered Institute of Personnel and Development, claims the real number could be up to a million.

The contracts are often used in the hospitality industry and in the care sector, which need access to a flexible pool of labour. The flexibility in the contracts means there is no obligation for companies to offer hours or for workers to accept them.

But Coles Miller employment law solicitor Amy Cousineau said all employers using the contracts should review them immediately.

“Employers typically use zero hours contracts to cover last minute events or peaks in demand,” she said.

“For this reason they tend to be associated with the hospitality and care industries which need regular access to flexible workers and would otherwise have to employ more expensive agency staff.

“But it looks as if the social tide is turning against zero hours contracts because they are perceived to be a less secure form of employment.”

Zero hours contracts are already illegal in France, Belgium and Spain – and the UK could follow suit in outlawing them, she said.

Ms Cousineau added: “Zero hours contracts may seem like a cost effective option but they are not without their pitfalls.”

She said some employers currently using zero hours contracts were planning to switch staff to fixed contracts – but that could come with difficulties of its own.

“Any change in contract terms has the potential to create loopholes or trigger unintended consequences so it makes sense to get expert legal advice,” she added.