The consumer champion carried out two separate surveys to get the views of more than 3,000 people in total and gauge their experience of trying to pay with cash.

The first survey was conducted over the phone to include consumers who may be less digitally capable and therefore potentially more dependent on cash. The second survey was online.

In the phone survey of 1,000 people, one in five (18%) reported being unable to pay with cash at least once when trying to buy something from April to July, during which time coronavirus restrictions were lifted for non-essential shops.

Of those who experienced cash refusal, one in six (16%) were then unable to pay for an item.

In a separate online survey of 2,000 consumers, respondents were most likely to be unable to pay in cash when shopping for groceries, which accounted for a third (35%) of incidents.

This was followed by small purchases in shops and buying refreshments whilst out and about such as getting a takeaway coffee (both 31%).

The refusal figures come despite around eight in 10 (84%) consumers thinking businesses and shops should continue to accept cash.

Which? is encouraging firms to sign up to its Cash Friendly pledge, an initiative designed to ensure that consumers who use cash regularly are not excluded by the transition to digital payments.

Jenny Ross, Which? money editor, says: “Over 200 businesses have signed up to Which?’s Cash Friendly pledge and we believe more businesses should commit to continuing to accept cash, helping customers for whom cash is a critical payment method.

“The government must press ahead with plans for legislation to protect cash and should make the FCA responsible for tracking cash acceptance levels. Encouraging cash usage also helps boost local economies since we know that those who take cash out are more likely to spend it locally.”