Britain opts out of the European 48-hour working week
The European Parliament's employment committee has voted to end the UK opt-out from the working time directive.
Labour MEPs were among those voting to axe the opt-out from the directive which seeks to limit the working week to a maximum of 48 hours.
The full European Parliament will debate the matter in December. Unions welcomed the move but businesses said it would damage their flexibility.
Prime Minister Gordon Brown wants to keep the opt-out negotiated in 1993.
The then Conservative government negotiated the opt-out for Britain from the Working Time Directive.
In June this year Britain reached agreement with other EU states that it could remain outside the directive, in return for agreeing to boost temporary workers' rights.
But that must be endorsed by the European Parliament and the committee voted by 35 votes to 13, to end the opt-out in three years.
Negotiations will now begin between the Parliament and EU employment ministers, ahead of a vote by the full Parliament in December.
Business Secretary Lord Mandelson said the committee's decision was "not surprising" but added: "We will continue to stand firm to protect the opt-out to the Working Time Directive's 48-hour maximum working week."
He said the opt out was "essential to Britain's labour market flexibility" adding: "People must remain free to earn overtime if they wish and businesses must have the flexibility to cope during busy times."
Conservative and Liberal Democrat MEPs also said the opt-out must continue. For the Tories, Philip Bushill-Matthews said the government should "give no ground" to the employment committee.
"It is imperative we secure a majority in favour of retaining the opt-out when the full parliament votes in December. It should not be the place of MEPs to tell people how many hours they can work."
For the Lib Dems, Liz Lynne said the vote put the government's "hard won deal to retain the opt-out" at risk.
She added: "Gordon Brown now faces a huge test of his leadership in securing the support of his own Labour MEPs, who have consistently voted to remove the UK's opt out of the 48 hour week."
Business groups also criticised the move, arguing that, during tougher economic times, firms needed more flexibility and people wanted the choice to work longer hours to make ends meet.
Deputy director general of the CBI, John Cridland, said: "We think people can look at their own circumstances and make their own decision about working longer hours. We call this common sense, and it doesn't need amending by Brussels."
But unions, which forced through a motion at the Labour Party conference in September calling for an end to the opt-out, welcomed the vote. Paul Kenny, of the GMB union, called it a "significant day for UK workers".
TUC general secretary Brendan Barber said workers would be "heartened" adding: "Our long hours culture, which has been shored up by the opt-out, has left many workers' health at risk."
Labour MEP Stephen Hughes, a member of the committee and spokesman for the European Parliament's Socialist group, told the BBC earlier it was "wrong in principle" to opt-out of what he described as a "health and safety law".
"I might be going against the government, but I am not going against the Labour Party. I think the government have got this wrong, frankly. They have been too close to the CBI."