In a consultative ballot of 10,000 GMB union members at British Gas, Britain's largest energy supplier, 95% voted in favour of industrial action, which could lead to a formal strike ballot in autumn, it said in a statement.
Centrica in June announced plans to cut around 5,000 jobs, as it ramps up restructuring efforts due to the COVID-19 pandemic.
"The company had burnt through the confidence of its loyal workforce by threatening to set fire to jobs, terms and conditions," the GMP said.
Centrica described their 'fire and rehire' plans as an 'insurance policy' and issued statutory HR1 and s188 notices which say this process could begin at the end of November, the union added.
(Reporting by K. Sathya Narayanan in Bengaluru; Editing by Gareth Jones)