A Trades Union Congress (TUC) survey of agency workers found that they want more rights and an end to pay discrimination.
The research revealed that a third of respondents said directly employed staff were paid more than temps for doing the same work.
Nearly half of individuals claimed they received less holiday entitlement and 28 per cent stated they lost out on overtime and unsocial hours payments.
Furthermore, three-quarters of respondents said temps were entitled to less redundancy pay, a situation which the TUC warned could make it hard for agency workers to plan ahead and cover bills in between assignments.
The TUC added that temps are usually the first to be made redundant.
Commenting on the findings, TUC general secretary Brendan Barber said: "The government must treat the introduction of the new regulations as a priority, to ensure that agency workers are protected and that the exploitation of temps by rogue agencies ends as soon as possible."
Some temps may be migrant workers and recruitment agencies are increasingly taking on people from Eastern Europe.
However, a study by University College London found that migrant workers from Eastern Europe have a positive affect on the UK’s economy.