Under government proposals, employees in "middle- class" occupations will be allowed to work more than 48 hours a week without formally "opting out" of the directive.
If they work longer than their contracted hours "voluntarily", the extra time would not count towards working time, although unions said employers would invariably "lean" on staff.
Stephen Byers, Secretary of State for Trade and Industry, said the amendments would help cut red tape without removing protection for workers. He also proposed that employers should not be forced to record hours worked by those who used the opt-out.
He said up to 2.7 million people in Britain worked more than 48 hours and most had officially agreed to work longer. He would be consulting for two weeks on the changes but it is thought possible the period might be lengthened. Union sources said New Labour "hawks" in the Government had sought even more radical changes but were fought off.
The proposals emerged after lobbying by Adair Turner of the CBI, who predicted "sighs of relief" if the amendments were pushed through. "Many managers and professional workers neither need or want a law forcing then to record the time they work."
He said the directive as a whole had sowed "confusion" and the confederation would strive with ministers to make it "even more workable".
But the MSF union, which covers white-collar and professional employees, said Mr Byers' proposals were "mad" and contravened the European directive. Roger Lyons, the union's general secretary, said he would be suggesting intervention by the European Commission and, if necessary, he would seek a judicial review.
On Tuesday unions declared their outrage over the Prime Minister's assertion that the Old Labour culture in the public sector was resistant to new working methods.
Referring to yesterday's proposals on working time, Mr Lyons said bad employers would be given a carte blanche to exploit workers. The time allowed for consultation was "pitiful". More then 5,000 people died every year from stress directly related to work and most of them were white- collar workers, he said.
Sir Ken Jackson, leader of the Amalgamated Engineering and Electrical Union, said the Government would be ill-advised to undermine a "family- friendly" policy which was popular with voters from all backgrounds.
The country's biggest union, Unison, said it was "galling" to see the Government chipping away at the regulations. Dave Prentis, deputy general secretary, said: "The Government talks about partnership but what sort of partnership allows one partner to exploit another?"Reuse content