Agency workers feel that they are treated as second-class citizens, a poll has found.
In a YouGov survey of temporary workers commissioned by the TUC, almost half of the 2,700 respondents said they receive less holiday than permanent colleagues, while one third said that they were paid less for doing the same work.
Three quarters of respondents said that they were entitled to less redundancy pay.
TUC secretary general Brendan Barber said: "The survey shows that many employers are using the lack of employment rights and insecurity of agency workers to treat staff badly: to pay them less, to give them less holiday pay, to get out of paying them redundancy or maternity pay, and to neglect their training and development."
The government consultation on giving agency workers equal treatment to directly employed staff after a 12-week qualifying period closes this Friday, 31 July.