British employees are currently free to work as many hours as they choose.

But recent rumblings from the European Commission suggest it might not be too long before workers are limited to putting in a 48-hour week.

Britain currently has an opt-out of the EU working time directive, which means individual employees can choose to work more than 48 hours.

But the opt-out, which was secured in 1993, is up for review this year.

Anna Diamantopoulou, the EU Commissioner responsible for employment policy, said: "The way British employers have implemented the opt-out is a very abusive one."

The Government said it would wait for the Commission's review later this year before commenting on the reports.

"So far we have yet to receive any formal proposals from the Commission," said a spokesman for the department of trade and industry.

"We are in favour of flexibility but also of minimum standards of protection of workers to ensure they can enjoy a work-life balance."

Nigel Costley, TUC secretary for the Swindon area, said trade unions backed moves to make it illegal for employees to work more than 48 hours per week.

"The idea that the British are happily working all those excessive hours because they want to do them beggars belief," he said.

"While some people will choose to work longer hours many do so because without them they wouldn't earn a decent wage."

TUC research showed more than 30,000 people in the South West were given no choice about signing their opt-outs.

"Only one in three people actually know there is a 48-hour limit," said Mr Costley.

Even those who were aware did not know how to enforce their rights or that it was possible to opt back in.

"With some exceptions and with sensible rules there should be a 48-hour limit on work time."

But Amanda Wilkinson of the Confederation of British Industry in the Swindon area said imposing a limit on working hours would be bad for businesses in Swindon.

"Companies have a number of working patterns, some of which require overtime to cover peaks and troughs in production," she said.

"There are businesses in the South West for whom a 48-hour week would be a problem."

Ms Wilkinson said the South West was the only region expecting an increase in employment in manufacturing in the next few months.

"Now is not the time to be creating further inflexibilities in the labour market," she said.

Swindon Pressings, the BMW-owned car manufacturing plant, said the opt-out was good for business.

"The current opt-out arrange-ment gives UK businesses competitive advantage over other companies and we will be monitoring the European Commission review closely," said a spokeswoman.