An average worker in Britain would earn an extra £4,500 a year if bosses paid for all overtime, according to the TUC.

Teachers and doctors are losing up to £8,736, while nurses and computer programmers may be short of £3,928, it claims.

A spokesman for the DTI told ePolitix.com: "People can't be forced to work unpaid overtime but be held to what they sign up to in their employment contract. No one can be forced to work more than 48 hours a week but they can choose to do so if they want to.

"We estimate that there are around three million people who work sustained long hours over the 17 week period. Around a third work long hours as part of their normal contracted hours, around a third work paid overtime, and around a third work unpaid overtime."

Forum Response: Institute of Directors

A spokesman for the IoD told ePolitix.com: "Official data actually shows that the average hours worked for a full-time employee is less than 40 a week, and surveys show that most long hours-workers do so voluntarily to further their careers and.

"The assertion that Britain works the longest hours in the EU is not strictly true and, globally, Britain has an average hours culture rather than a long hours culture."