The Unite union has called on the Government to reverse its decision to cut winter fuel payments for millions of pensioners or warned it could face judicial review.
The government announced plans to cut most pensioners' payment, worth between £100 and £300, in July, a move confirmed in the autumn budget.
Labor faced criticism over the move, which Chancellor Rachel Reeves said she had taken in order to help plug a £22 billion hole in the public finances.
Unite general secretary Sharon Graham said in a statement that “it is not too late for the Labor Party to wake up to the harm this cruel policy has caused, to stop picking the pockets of retirees and do the right thing.”
An estimated 10 million retirees will lose their fuel payments in winter. The benefit will still be paid to those who receive pension credit or other means-tested support.
A pre-action letter from Unite's legal representation, sent to the government on October 29, claimed the government had failed to carry out a full assessment of the impact of the decision on the population.
The government revealed in September that there had been no wide-ranging review, but a more limited “equalities analysis” was published.
The letter named Works and Pensions Secretary Liz Kendall as a proposed defendant. The government technically has 14 days – until November 12 – to respond, although the union has requested a response by November 7.
The government has been contacted for comment.
The letter also said the government had a legal duty to submit the reduction to the Social Security Advisory Committee and should have gathered more evidence on the impact, particularly on vulnerable and disabled people, by law .
The issue was “urgent” due to increasingly cold weather and the significant impact on people “who are at risk of being disconnected and increasingly having to forgo adequate heating and cut other essential expenses “, the letter states.
“People don't understand, I don't understand how a Labor government has cut the fuel allowance for millions of pensioners as winter approaches,” Graham added.
Prime Minister Keir Starmer previously defended the “difficult” decision to scrap basic income.
Sir Keir said the cut was necessary because of the state of the country's finances, accusing previous governments of avoiding tackling issues such as the cost of fuel in winter.
In Scotland, a couple were also allowed to launch their own legal action against the UK and Scottish governments over the removal of the benefit.