Ambulance staff from five services will strike on February 10, in new strike action by Unison.
Ongoing disputes over pay and staff are yet to go resolved, resulting in walkouts for workers in London, the South West, Yorkshire, the North East and the North West.
There will be NHS strikes every day next week except Wednesday.
Unison urged the government to stop “pretending the strikes will simply go away” and act now to end the dispute by boosting pay packets.
Calls for “actual talks”
The union also said that unless the government agrees to “actual talks”, it could announce more walkouts in March.
The latest strike announcement comes as ministers are braced for the biggest day of industrial action in over a decade on Wednesday, February 1 when teachers, university lecturers, train drivers, civil servants, bus drivers and security guards all stop work.
Unison’s head of health Sara Gorton said: “Ministers must stop fobbing the public off with promises of a better NHS, while not lifting a finger to solve the staffing emergency staring them in the face.
“The government must stop playing games. Rishi Sunak wants the public to believe ministers are doing all they can to resolve the dispute.
“There are no pay talks, and the Prime Minister must stop trying to hoodwink the public. It’s time for some honesty. Ministers are doing precisely nothing to end the dispute.”
Downing Street said the latest strike announcement by ambulance workers is “deeply concerning”.
“We are putting in place significant mitigations that have previously helped reduce some of the impact from these strikes,” the PM’s official spokesperson said.
“But first and foremost we would ask the unions to reconsider that approach and continue discussions.”