DTI chief Stephen Byers has promised to put back the implementation date for the Part-Time Work regulations by almost two months in a major concession to employers.
The eight-week delay was announced in a speech to the British Chambers of Commerce just four days before the law was due to come into effect on 7 April.
He told employers that consultation responses were still being considered, but promised that the regulations will be out shortly.
"Last year I said I would give business six weeks between publication and entry into force of regulations. When the Part-Time Work rules are published I intend to allow at least eight weeks for business to prepare before they come into force," he said.
The news was greeted with relief from employers who were expecting to have to meet the 7 April deadline.
Anne Minto, HR director at Smiths Industries, said that, unlike other pieces of legislation, employers will now have enough time to become conversant with the law first.
"We will also be able to advise employees as to what is in the regulations as far as their rights are concerned," she said.
Francesca Okosi, HR director at the London Borough of Brent, also welcomed the delay, but added that eight weeks may not be sufficient.
"It depends what the regulations say. For local authorities it will probably be long enough because we already have equal rights for part-timers in our terms and conditions, but in some sectors employers will have a long way to go.
"This is an improvement but it is still not ideal. There seems to be a lack of awareness that employers have their day jobs to do as well."
Bruce Warman, HR director at Vauxhall Motors, said he hoped the delay was an indication that the Government is finally listening to employers' calls to be given enough time to consult on and implement laws.
The Government has still not decided if the law will apply to "employees" or the wider definition of "workers".