A major trade union has threatened legal action over the Government’s decision to means-test winter fuel payments.

Around 10 million pensioners will no longer receive the benefit from this winter after the Government decided to restrict payments to people on pension credit in a bid to save money.

Ministers said the move was necessary to help fill a £22 billion “black hole” they claim the previous government left in this year’s spending plans.

But the trade union Unite said it believed the cut to winter fuel payments would have a “terrible effect” on millions of pensioners and demanded the Government reverse its decision or face a judicial review.

Unite general secretary Sharon Graham said: “People do not understand, I do not understand how a Labour government has taken away the fuel allowance of millions of pensioners just as winter approaches.

“Given the failure to rectify this in the budget, Unite has now commenced judicial review proceedings challenging the legality of the policy.

“It is not too late for Labour to register the hurt that this cruel policy has caused, step back from picking the pockets of pensioners and do the right thing.”

The union said it believed the Government had breached its legal duties by not referring the cut to the Social Security Advisory Committee (SSAC) and by failing to consider the impact on disabled people, among other grounds.

Ministers are not required to refer regulations on benefits to the SSAC if they are a matter of “urgency”, something the Government relied on when implementing the winter fuel cut.

The Government also conducted an “equalities analysis”, which was released under the Freedom of Information Act, but has been criticised for not carrying out a full impact assessment of the policy.

Unite has given the Government until November 7 to respond to a pre-action letter sent last week and reverse the cut, otherwise it would request permission from the High Court for a full judicial review.

The push for a judicial review of the policy will further strain relations between Labour and Unite, which had previously been a significant donor to the party.

The union has already expressed opposition to the winter fuel payment cut, staging a protest outside this year’s Labour Party conference over the issue.

A Government spokesperson said: “We are committed to supporting pensioners – with millions set to see their state pension rise by up to £1,700 this parliament through our commitment to the triple lock.

“Over a million pensioners will still receive the winter fuel payment, and our drive to boost pension credit take up has already seen a 152% increase in claims. While many others will also benefit from the £150 warm home discount to help with their energy bills over winter.”