The British government will announce legislation in the coming days that will allow employers to fire striking workers in essential sectors and sue unions if they fail to provide minimum levels of service, said a person familiar with the matter.

The law was promised late last year by Prime Minister Rishi Sunak in response to a wave of strikes over the winter that saw strikes by nurses, ambulance drivers and train staff.

Sectors covered by the new law will include the National Health Service, railways, teachers, firefighters and the nuclear sector, according to the person, who spoke on condition of anonymity about plans yet to be finalized. If staff and unions fail to provide a minimum level of service in the area, they could face legal action or dismissal for breach of contract, the person said.

The law could be introduced to Parliament as early as next week. The Times first reported the story.

The UK has been hit by a growing wave of strikes which in December resulted in perhaps the biggest monthly loss of a working day due to industrial action since 1989, when Margaret Thatcher came to power. They were among the first nationwide strikes by nurses, protesting against wages failing to keep pace with skyrocketing inflation.

The government expects some opposition to the law in the House of Lords, whereby some associates may try to water down its provisions, while unions may try to fight it in court.

Labor leader Keir Starmer, whose party enjoys a double-digit lead in opinion polls, told reporters on Thursday he would withdraw the law if he became prime minister.

“When it comes to more restrictions, we’ll lift them,” Starmer said. “I don’t think the law will work,” he added, saying he suspected the government had taken advice suggesting it was “likely to make a bad situation worse.”