She warned: “I must stress, experts warn that when you claim pension credit you must ask for back dating as it won’t be done automatically.

“Also, the rules make it clear that even if you just get one penny a week in Pension Credit, you will get the full £650 cost of living payment.”

Paul Lewis, presenter of Money Box, added: “That’s a bargain!”

Those interested can call 0800 991234, if they have a low income and they and their partner are at least 66.