Hundreds of British Gas workers were sacked last month after refusing to sign up to detrimental changes to their terms and conditions. The move came after numerous days of strikes which caused significant disruption to British Gas customers needing servicing and repairs appointments.

Their union GMB says many opened their final pay packet to find they have been put on a self-assessment tax code, meaning many have had more than £1,000 incorrectly deducted from their wages. Whilst this change appears to be an instruction made by HMRC, it still comes as a shock to the sacked employees who were not expecting further reductions to their final pay packet.

Meanwhile Centrica CEO Chris O’Shea, who has been heavily criticised for the company’s fire and rehire scheme, has been handed a shares award worth almost £2m on current prices.

The chief executive has also ended a voluntary salary reduction of £100,000 – meaning that his salary before benefits, bonuses and shares has increased from £675,000 to £775,000 this year (a rise of 15%).

Andy Prendergast, GMB national secretary, said: “These engineers have lost their livelihoods because they refused to accept draconian cuts to their terms and conditions.

“To see their final pay packets incorrectly taxed by more than £1,000 is yet more scorn from a company that has treated loyal workers with utter contempt. We acknowledge this appears to be a result of a HMRC instruction, but the failure to give sacked workers prior notice has done nothing other than add insult to injury.

“At the same time, the company sees fit to reward a CEO who sacked his own highly skilled, qualified and experienced workers because they would not submit to his reckless bullying. Surely that’s a measure of failure, not success?

“The revelation that Chris O’Shea has been handed shares worth almost £2m will come as a kick in the teeth to thousands of British Gas workers. The news that he will also be paid an additional £100,000 in salary this year while our members are denied time with their families will add more salt to the wound.

“Until British Gas starts rewarding the company’s greatest asset – the workers – and reign in its grotesque corporate largesse, it will continue to flounder.”