Building and construction unions have been the target of a Queensland government overhaul of regulation which the government and employers say will crack down on militant union representatives using safety as an excuse to force their way onto worksites but which unions say places workers at risk.

Passed into legislation last week, the Work Health and Safety and Other Legislation Amendment Act 2014 requires holders of work health and safety entry permits or those assisting them to give at least 24 hours’ notice before entering a site and doubles penalties for union officials and others who breach…