The concept of overtime no longer applies to many employees whose careers do not adhere to "a strict time schedule".

That is according to Mike Emmott, employee relations adviser for the Chartered Institute of Personnel and Development (CIPD).

Mr Emmott explained that "the lines between work and play are blurred" because many employees think about their jobs in their spare time.

He said, however, that "we broadly agree that we don’t want a long hours culture because long hours can be damaging to health, social life and performance in the office particularly if it is not the choice of the individual worker".

While the current economic climate does not make overtime an inevitability, he suggested that certain employees feel the need to work extended hours to show their commitment.

According to analysis by the Trades Union Congress of official statistics published in February, those who work in research and development, finance and public administration are the most likely to have been undertaking unpaid overtime in the recession.