The UK government is reportedly preparing to repeal a legal ban on the use of agency staff to fill in for striking workers, according to a report in The Guardian.

Following an announcement by rail union RMT that 50,000 railway workers would participate in a three-day national strike later this month, UK Transport Secretary Grant Shapps said that the government is looking to remove a legal restriction that prevents employers from taking on agency workers to cover work done by striking staff.

The strike is scheduled to begin June 21, when more than 50,000 railway workers will walk out, affecting Network Rail, 13 train operating companies and London Underground. On June 23 and 25, up to 40,000 workers will walk out, affecting Network Rail and 13 train operating companies.

The move to repeal the ban on agency workers filling in for striking workers faces criticism, however. The Recruitment & Employment Confederation, which represents recruitment firms in the UK, warned that removing the ban places workers at risk.

“Repealing the ban on agency workers replacing workers who are on strike is the wrong policy,” said Neil Carberry, chief executive of the organization. “It puts agency staff and agencies in a completely unfair position. Government’s focus, like any other employer, should always be on trying to resolve the issues in an industrial dispute. The REC will strongly oppose any moves to change the law.”