Management executives' are exempt from the directive

The European Union Working Time Directive, which sets a limit of 48 hours' work a week, will be extended to groups of workers not previously covered by the rule on 1 August, the Department of Trade and Industry said.

Oil rig workers and train drivers are among the workers that will be brought under the directive, while the 48-hour limit will be phased in more slowly for trainee doctors.

"Other industries have coped well with the regulations and we are confident they can be implemented in these sectors without affecting employment prospects," said employment relations ministers Gerry Sutcliffe.

The law also sets out workers' rights to rest breaks, holidays, and restrictions on working at night.

Work sickness

The Working Time Directive was adopted the UK in 1998, but swathes of the workforce were exempted from its provisions.

Working time directive rules Employees can refuse to work more than 48 hours a week Workers entitled to 20 days annual leave (pro rata if part-time) Rest break entitlement and can refuse to work more than eight hour night shifts Source: DTI

Trade union groups said extending the directive will redress an imbalance.

"This move is to be welcomed. Working long hours leads to a greater chance of physical and mental ill health, and leads to more accidents," a spokesman for the Trades Union Congress (TUC) told BBC News Online

However, the TUC says the directive has had little impact on the UK's long hours culture.

It said this is partly because employees can choose to opt out from the directive, while those deemed to be 'management executives' are exempt.

"The term executive has been used very broadly to exempt large numbers of office workers," Mr Sellers said.