British Gas engineers are to stage a fresh strike in a continuing dispute over pay and conditions.
Members of the GMB union will walk out on April 14, which will be the 43rd day of industrial action this year.
The GMB said engineers face being sacked on the same day if they have not signed up to new contracts which the union claims will lead to pay cuts of 15% and other changes.
British Gas denies the union’s claims.
GMB national officer Justin Bowden said sacking highly skilled, qualified and experienced workers is the “ultimate measure of failure” by the company.
“The British Gas workforce are united in utter disgust and anger against the Centrica senior management team,” he said.
“This disgust and anger will be manifest across the country on April 14.
“This dispute is far from over. It brings to mind the old adage that ‘any fool can start a war’.”
A spokesman for British Gas owner Centrica said: “There is a job for everyone at the end of this process. Well over 95% of the company have signed up to the new contracts and our new terms are fair and highly competitive.
“We’re not cutting base salaries or changing our generous final salary pensions. Our gas service engineers will remain some of the best-paid in the sector, earning £40,000 a year minimum.
“The changes will be in place from April but there is still time over the next few weeks for those who haven’t signed up to change their minds.
“We have a responsibility to give our customers the service they deserve and in doing so protect the future of 20,000 highly paid UK jobs.
“So, while change is difficult, reversing our decline, which has seen us lose over three million customers, cut over 15,000 jobs and seen profits halved over the last 10 years, is necessary.
“The changes will also unlock our ability to grow jobs and hire 1,000 green apprentices over the next two years.”