More than 260,000 pensioners who are yet to pay for their TV licences will face demands from the BBC next month.
The universal right to a free TV licence finishes for all over-75s and only those in receipt of pension credit do not have to pay.
Pensioners were given a grace period to make arrangements because of the Covid pandemic, but the BBC has confirmed this will come to an end on July 31.
The corporation said more than nine in 10 over-75s households have now made arrangements for a free or paid licence, or updated it on changes in their circumstances.
But furious campaigners warned that the BBC could be forced to take thousands of OAPs to court for refusing to pay.
Dennis Reed, director of campaign group Silver Voices, said: “A year on from the scrapping of free licences, a significant hard core remains of over 75s who are refusing or unable to pay.
“Is the BBC going to fine and potentially take to court, hundreds of thousands of senior citizens who are standing out against the scrapping of this welfare benefit?”
He urged the Government to to intervene urgently to reach a solution.
“Is the Government really prepared to see large numbers of people in their 80s and 90s, who have paid tax all their lives, and sometimes served in war for the country, fined up to £1000 and then carted off to jail for non-payment of a TV licence?” he asked.
The BBC said it will be writing to the 260,000 people who are yet to make arrangements and will include information about where help is available.
BBC director-general Tim Davie previously has signalled that over-75s will not be threatened with legal action over non-payment.