Agency workers staged protests outside call centres across Britain today, claiming that a loophole in the law is denying them the right to equal pay.
The Communication Workers Union (CWU) said that under the Agency Workers Directive all agency workers should receive the same rates as other workers after 12 weeks in a job.
But the union said many agency workers are signing away their rights without realising what they are doing - costing some employees more than £500 a month.
Hundreds of workers braved arctic conditions to take part in demonstrations in areas including Blackburn, Canterbury, Doncaster, Lancaster, Lincoln, Nottingham, Dundee and Glasgow.
CWU general secretary Billy Hayes said the legal contracts were unfair and morally wrong in the same way companies avoid paying their fair share of tax.
"Agency staff earning less than the living wage are losing out to the tune of £500 or more a month. They're entitled to equal pay but are being exploited. This loophole should be closed," he added.
Scottish TUC said it strongly supported the CWU's day of action.
As Aslef's annual assembly of delegates begins in Edinburgh tomorrow the general secretary explains the challenges his members - and workers across the country - face