Labour leader Keir Starmer is backing calls to save free TV licences for people over 75.
Millions face losing the benefit and paying £157.50 from August after the Tories broke a manifesto pledge.
The curb was due to come into force on June 1 but was delayed by two months due to Covid-19.
Campaigners hope the Government and BBC can strike a deal to save the lifeline – with a minister due to be quizzed in Parliament today.
Mr Starmer, who had a haircut at his local barbers on Saturday, to show Britain is open for business again, said: “TV has been essential for many of our older population during the crisis – especially as many have been stuck at home throughout such a difficult time.
“Hundreds of thousands will struggle to pay this and could be forced to choose between paying their TV bill or their heating bill this winter.
“The idea that you could take away so many people’s connection to the outside world is cruel.
“It’s simply not good enough for the Government to pass the buck and blame the BBC.”
The Conservatives pledged at the 2017 election to protect free licences for the rest of that Parliament, which was due to run until 2022.
But the BBC had been given responsibility for funding the lifeline from June 2020, under a deal agreed in 2015.
It says keeping licences free will cost £745million by 2021-22.
So the corporation is introducing restrictions, meaning only over-75s who receive Pension Credit will be eligible. An estimated 3.7 million OAPs are due to miss out.
The Mirror is fighting to permanently save the benefit, with over 18,000 readers backing it.
Silver Voices director Dennis Reed said: “This endorsement of the campaign for free TV licences by the Leader of the Opposition is fantastic news.
“The campaign is now raised to the highest level of UK politics.
“Boris Johnson will no longer be able to wash his hands of the whole affair and leave the plight of millions of older people, who will be unable to afford the £157.50 fee, in the hands of the BBC.
“After all, the Conservative Government forced the BBC to take on responsibility for this welfare benefit and then cut off the funding for it.
“This intervention by Sir Keir should persuade the Prime Minister that he will not escape responsibility if the free licence is scrapped and should force a rethink of the Government approach.”
Betcu broadcasting union head Philippa Childs said: “We know across the political spectrum there are serious concerns about the repercussions of the BBC taking on responsibility for licence fees for the over-75s.
“Sir Keir Starmer’s decision to speak out about this issue should not be underestimated.
“The decision to pass over this welfare benefit to the BBC is coming under increased scrutiny.
“The BBC’s role is to inform educate and entertain the nation, not make welfare or benefit decisions – that is the role of Government.
“It is clear that this additional expense will only lead to increased pressure on our members and content being compromised.
“The Government must now reconsider its position.”
Age UK charity director Caroline Abrahams said: “Keeping access to TV free for our over-75s was always the right thing to do before the pandemic struck and that’s even more the case as things are now, with the coronavirus having receded to a degree but still presenting a mortal threat to everyone in this age group.
“This issue ought to be above politics – it’s a matter of doing the right thing by our oldest citizens as we hope that every politician will agree, regardless of party.”
A BBC spokeswoman said last week: “The Government decided to end the free TV licence for the over-75s and gave the BBC Board responsibility to decide on its future.
“We consulted with the public and reached the fairest decision possible, to support the poorest oldest pensioners.
“We delayed the introduction of the new scheme until August as a result of the pandemic, and we are keeping that decision under review.
“During lockdown the BBC has played an important role informing, educating and entertaining all our audiences, including older people.
“The Board will announce its decision this month.”
The PM has urged it to “cough up” and save free licences.