MPs have backed a bill extending employment rights to temporary and agency workers.
The Temporary and Agency Workers (Equal Treatment) Bill was passed at its second reading with 147 MPs voting in favour and 11 against.
Ellesmere Port and Neston MP Andrew Miller brought forward a private members' bill on the issue and is being backed by many Labour colleagues despite government opposition.
Under pressure from leading unions, many Labour MPs stayed in Westminster to support the legislation.
Ministers warned the move could hinder British business - with the CBI saying 250,000 jobs could be lost.
Gordon Brown has offered to establish a commission chaired by Sir George Bain – head of the Low Pay Commission – to look at the matter.
But Miller told ePolitix.com earlier this week that there was both an "economic" and a "moral" case for the Bill.
"In economic terms, we are not going to succeed if we try and undercut the lowest terms and conditions of employment in the world, we are going to succeed if we have a highly skilled, highly trained workforce," he said.
"The way in which a lot of employers are using agencies to drive down pay and conditions is not a long-term, constructive solution; it's good old British short-termism which is good for just that but not good for Britain in the world as portrayed by the prime minister in his speech at Davos.
"Years ago we started the process of creating equality between men and women in the workplace. Now I'm just adding to that and saying there should be no difference between how temporary workers and permanent staff are treated."
Miller is re-introducing a measure that Newcastle-under-Lyme MP Paul Farrelly attempted to push last year. And having been drawn third in the ballot for backbench bills, he stands a good chance of receiving enough parliamentary time to pass the Bill if he can reach a compromise with the government.
