The European Parliament has voted to scrap the UK's opt-out clause for Europe's Working Time Directive (WTD).
The clause, introduced in 1993, has enabled UK businesses to ask employees if they are willing to work longer than the maximum 48 hours per week in the European legislation.
Business groups say the opt-out is needed as it offers companies more flexibility in hiring staff and organising rosters.
However, the European Parliament seems determined to remove the clause when the directive is updated, and last week backed plans to drop the opt-out clause by 2010.
The opt-out clause does not solely apply to Britain, but has been used more here than in other European countries.
The UK government has backed the retention of the clause, but opposition parties have warned that Labour MEPs may not follow Downing Street’s lead when voting for changes to the WTD.
David Yeandle, deputy director of employment policy at the manufacturers' organisation EEF, said: “MEPs had the chance today to prove their commitment to the cause of labour market flexibility and economic growth; unfortunately the majority of them have fluffed their lines.”
“Thankfully this is not the end of the story and we look to the UK government to continue to lobby for the retention of the opt-out and work with other member states and the Commission to reach a solution."
Because the proposals involve a “codecision” between the European Parliament and the Council of Ministers, there could be further amendments to the directive.
A report presented to the parliament, drafted by Spanish socialist MEP Alejandro Cercas, also called for any time workers spend on call to be regarded as working hours.
Legislation will go before the Council of Ministers in the next two months, and will then return to the parliament for second and third readings.
Speaking before the vote last week, Cercas described the opt-out clause as a “dagger in the heart” of the idea that Europe be comparatively proactive in safeguarding workers' rights.
His comments reflect fears among MEPs that Eastern European countries will look more toward more flexible British workplace practices, rather than the comparatively stricter controls in France and Germany, when they join the European Union.