New figures obtained by the consumer champion show fees of at least 95p per withdrawal were imposed on 1700 non-bank operated machines between January and March this year, with 1250 of these conversions taking place in March alone.

Most of the ATMs affected are operated by Cardtronics - the UK’s biggest cashpoint operator - which has warned it is likely to convert a further thousand machines to charge fees in the coming months.

Notemachine, another major cashpoint provider, has cautioned that it is considering converting up to 4000 machines in its 7,000-strong network to charge fees due to changes in how Britain’s biggest network of ATMs is funded.

If these plans go ahead, Britain stands to lose more than one in 10 of its free cashpoints in a matter of months, says Which?.

The consumer group is concerned that the cost of cash withdrawals has been shifted from banks to consumers, with poor and vulnerable people - who are most reliant on cash to pay for goods and services - hardest hit by the change.

The urgency of the problem was reinforced by the recent Access to Cash Review, chaired by former Financial Ombudsman boss Natalie Ceeney, which reported that the UK’s cash infrastructure was “on the verge of collapse”.

The consumer champion is calling on Government to appoint a regulator to protect consumers and businesses and properly manage the cash landscape to ensure no-one is denied their ability to access cash.

Gareth Shaw, Head of Money, Which?, says: “Communities are being stripped of free access to cash at an alarming rate that could hit the most vulnerable in our society the hardest, while denying millions of people free withdrawals.

“A regulator is desperately needed to get a grip of these rapid changes across the cash landscape and ensure all those still reliant on this important payment method aren’t suddenly shut out from accessing the cash they need in their daily lives."