The research compiled by the employment regulations organisation revealed that just six per cent of companies with fewer than ten staff had made changes.

New age discrimination legislation came into force in October last year but firms were quick to point out that they felt their policies complied with the new regulations or did not apply to their business.

Although two thirds of respondents thought they were well informed about the legislation, fewer than 30 per cent answered correctly about whether there is an age at which employees should expect to retire.

Acas chairperson Rita Donaghy said the results were worrying and that she felt if age laws weren't considered, tribunal cases could potentially harm smaller companies.

She said: "Age discrimination can affect all employees, young and old and to comply can be very simple and quick.

"We are urging businesses to act now, helping them to put in place policies that minimise the risk of prosecution and to make employment decisions on the basis of talent and skills alone."