It feels to Tom Sturr sometimes as if the whole of London is permanently running late. All around him, people speed up, check imaginary watches and rearrange their faces to look suitably “harried” as they pass. “I had no idea that all these professional people were such bad time-keepers,” he deadpans. “It's slightly worrying.”

Today, on Sturr's patch just off Oxford Circus, Central London, similarly alarming numbers have come out shopping with no money. One lady, of questionable age, has to breast-feed a baby. Others do not even offer any such excuse, just a shake of the head and a side step.

Who on earth would choose to be a chugger? Surely no pay packet in the world - and certainly not £7.50 an hour - could make up for the daily abuse, rejection and the one-size-fits-all uniform.

And this week, to make it worse, the charity watchdog, Intelligent Giving, has claimed that many chuggers - a conflation of charity and muggers - may be breaking the law by harassing shoppers and failing to disclose that they are being paid. The watchdog has urged the public to boycott the collectors.

Sturr, a self-confessed idealist, rejects the Intelligent Giving allegations. He is saving up to travel to Nepal where he wants to live in a monastery and meditate. He has floppy hair, big eyes and “chugs” by the book, bounding from one refusal on the street to the next with exuberance.

He is, like most chuggers, just trying to earn money in an economy that has offered him few other job opportunities. He received two days' training and, six weeks in, has already lasted far longer than most in a business where the turnover reaches hundreds of people every month. Sturr is now under huge pressure to meet his target of ten donors a week. Fail and he will be unceremoniously sacked.

Beneath the pragmatism involved, however, there is invariably passion as well. “At the beginning, chuggers are often in it just to earn money,” Sturr says. “But when you are repeating these harrowing facts hundreds of times a day, it starts to affect you.

“You see these people in fur coats carrying £3 cups of coffee and big shopping bags and claiming they can't afford £5 a month because of the credit crunch. It's so frustrating. But once you get over that, it can be great, rewarding work.”

Around the corner, chuggers for one of the largest street fundraising companies in the UK gather for a group hug and a motivational talk from their team leader.

“Is it OK for people not to donate?”

“No!” the team cries.

“How much per day is £5 a month?”

“15p!”

These are dedicated chuggers. When dressed in the company's uniform, their employers insist that they are not allowed to go near anything that they claim is “unethical” - global corporations such as McDonald's, Starbucks, Cadbury's, Coca-Cola. They often work late into the evening and face abuse from critics.

“A lot of people disagree with us being paid, but charities are businesses and their ultimate goal is to maximise profits,” says one chugger, Suzy. “Charities would not use chuggers if we were not the most effective way of doing this.”

Mick Aldridge, the chief executive of the Public Fundraising Regulatory Association, which oversees 95 per cent of the organisations involved in street fundraising, called Intelligent Giving's survey “grossly irresponsible”. Aldridge, whose association enforces a code of conduct through regular spot checks, says that a chuggers boycott would deprive charities of £25 million a year.

Suzy, in her early twenties, describes the racist abuse and sexual slurs that she has received in a mere three weeks on the job. “I've had people saying that they hate me and they'll take me to court for harassment - even though we were taught in our training never to follow someone for more than three steps. I know what qualifies as harassment better than any of the public.”

City types, known simply as “suits”, are the worst, especially now with the financial recession, Suzy claims. “A suit came up to me recently and said what I was doing was offensive.

“People tell us all the time that they would prefer to give to charity on their own rather than be pressured into it by us, but the fact is that the vast majority don't. We are just doing our job - and it is a really useful job. Hug a hoodie? It should be hug a chugger.”

Some names have been changed in this piece

Sweet charity by numbers

£25 million: The amount raised by chuggers every year

1997: The year chugging arrived in Britain from Austria

£5: The amount raised for every £1 spent on street fundraising

28p: The amount given by the Treasury under its Gift Aid scheme for every £1 donated by direct debit

Sources: DialogueDirect, charityfacts.org pfra.org.uk

Top Five reasons for not giving

1. Running late

2. No money

3. Already signed up to another charity

4. Don't believe in street fundraising

5. Credit crunch

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