The are 1.3million agency workers in Britain
New measures giving Britain's temporary workers equal rights to permanent members of staff have been agreed by European Union employment ministers.
The move aims to give temporary workers the same rights in areas like holiday and sick pay as permanent colleagues.
The Luxembourg talks also confirmed the UK's opt-out from the working time directive and a maximum 48-hour week.
Business Secretary John Hutton described the 12-hour meeting's outcome as "a very good deal for Britain".
Under the deal, Britain's 1.3 million agency workers will get the same pay and conditions as permanent staff after being employed for 12 weeks.
The government had rejected original EU proposals to grant equal rights from the first day of an agency contract, suggesting temps should have at least one year's service to qualify.
Last month Mr Hutton accepted a national agreement between the CBI and TUC for parity after 12 weeks which unblocked the stalled EU negotiations.
In return for dropping their long-standing opposition, British ministers secured a firmer opt-out from the working time directive, which limits workers to 48 hours each week.
Mr Hutton said the deal retained crucial job market flexibility.
He said: "It provides a fair deal for workers without damaging Britain's economic competitiveness or putting jobs at risk.
"Flexibility has been critical to our ability to create an extra three million jobs over the past decade. That flexibility has been preserved by ensuring workers can continue to have choice over their working hours in future years."
Critics of the deal include small and medium-sized employers who say they will be hit hard by the measures.
A number of EU countries have criticised the British opt-out on working hours.
The measures now go to the European Parliament, where there will be attempts to strengthen protection for workers further.