The TUC has called on the government to close a loophole in the law which allows employers in the shipping industry to pay migrants much lower wages than UK crews.
Under UK law it is lawful for ship owners to pay migrant seafarers substantially less per hour than the British crew members they work alongside, the union said.
Last month Irish Ferries was involved in a dispute with workers over plans to replace 540 employees with foreign workers.
Frances O’Grady, TUC deputy general secretary, said: “This allows shipping employers who want to keep their costs down to do so by employing migrant workers on poverty pay, and laying off workers to whom they are legally obliged to pay the minimum wage.
“This is because the Race Relations Act contains an exemption allowing ship owners to blatantly discriminate on pay rates on the basis of nationality. This practice is widespread in the shipping industry.”
The TUC will be pressing ministers to amend the Race Relations Act so that these pay practices against seafarers will be outlawed.
“The European Commission, the UK government and unions all have legal advice that underpaid seafarers from EU countries will have good claims to challenge pay discrimination on any ships with a connection to a EU country,” O’Grady said.