WHSmith is allowing the unpopular practice of face-to-face charity fundraising to be carried out in its stores as part of a trial that observers are calling risky.

The general merchandiser is allowing clipboard-wielding fundraisers – often referred to as “charity muggers” or “chuggers” – from the British Red Cross to approach shoppers as they enter stores and while they browse books or magazines.

One shopper at the Holborn Circus branch in London was approached twice in five minutes by two different but equally persistent fundraisers last Thursday.

WHSmith declined to comment on any commercial aspects of the relationship, but the Red Cross states on its website that the process of “private-site fundraising” is carried out by external agencies on its behalf and that those agencies pay a fee to operate on private sites such as shops.

A WHSmith spokeswoman said: “As a company we have nominated charities that we support throughout the year. Last week, we ran a trial in our Holborn Circus store with the Red Cross. As with any trial we run, we will evaluate customer response as soon as it is complete.”

However, a source close to the Red Cross said she believed the charity has been sending fundraisers to WHSmith stores since November, including shops in Peckham and Stratford in London.

Retail Knowledge Bank senior partner Robert Clark warned against the practice. “I’ve not heard of it before. I suspect it will irritate a significant proportion of customers. WHSmith will have to watch it very carefully. Those workers are tarred with the brush of the more pushy and irritating charity collectors. WHSmith is treading a fine line.”

The retailer was expected to reveal its interim results as Retail Week went to press.