The government announced plans to change the law on proxy workers.
It will enable companies to provide skilled workers during industrial strike to fill in the gaps.
Under current trade union laws, recruiters are prohibited from providing temporary employees to cover strikers.
Ministers say that could have a “disproportionate impact”.
The legislation would remove what are described as “onerous” legal restrictions.
Agency staff can then be made available at short notice.
“Removing these 1970s-era restrictions will give companies free access to fully skilled employees quickly, while allowing people to get on with their lives without interruption to help keep the economy volatile,” said Business Minister Kwasi Quarting.
Network Rail welcomed the move, but Labor and unions described it as a “recipe for disaster”.