Gordon Brown has been defeated by his own MEPs after the European Parliament voted to scrap Britain’s exemption from EU laws banning employees from working more than 48 hours a week.

Bizarrely, the Government depended on West Midlands MEPs Philip Bushill-Mathews and Liz Lynne, a Conservative and Liberal Democrat respectively, to put its case - after Labour members refused to back it.

But this wasn’t enough to save it from defeat, after the European Parliament voted to scrap Britain’s opt-out from the Working Time Directive. Up to three quarters of Labour’s 19 MEPs rebelled to defy the Government and join their colleagues in the Socialist group in Brussels to oppose the Government’s position.

The directive is designed to prevent staff being pressured into working long hours by their employers. However, workers in some countries including the UK are allowed to opt-out of the rules, which means they can enter into voluntary agreements with their employer agreeing to work longer hours.

Trade unions have been pushing for the opt-out to be scrapped, arguing that some employers pressure staff into signing away their rights. Britain’s Labour Government wants to keep the opt-out, but the campaign to abolish it is backed by many Labour MEPs.

It has meant Ministers were co-ordinating their campaign to keep the law as it is with politicians from rival parties, such as Mr Bushill-Mathews, leader of the Conservative group in the European Parliament, and Ms Lynne, Shadow Rapporteur for the Alliance of Liberals and Democrats for Europe.

The European Parliament does not have the final say, as the Council of Ministers - which represents the Government’s of member states - wants to keep the opt-out. Mr Bushill-Mathews said: “Socialist MEPs have won the battle today, but they must not be allowed to win the war. The British government must dig in and defend the opt-out.”

Ms Lynne said: “The UK Government should have been able to rely on all their own MEPs to support them in the retention of the opt-out but that was not the case.” Birmingham Chamber of Commerce said it was “extremely disappointed” by the result of the vote.

Katie Teasdale, head of policy at the Chamber, said: “This decision will negatively affect the competitiveness of UK firms at exactly the wrong time.”

But trade union Unison was delighted. General Secretary Dave Prentis said: “People in the UK work some of the longest hours in Europe which is no recipe for a healthy or productive workforce.”