'We want to be world class," says Errol Damelin, talking about his high-profile start-up, Wonga. "And I don't mean bigger than Barclays. I mean like Facebook, Amazon and Apple."

Fantasy? Well, the smart-talking South African entrepreneur is certainly making a strong case. His company looks set to transform personal finance as it makes the process of borrowing money completely automated.

Wonga is the online, short-term money-lender backed by some of the world's top venture capitalists. Launched in 2007, the multi-million pound start-up is Europe's fastest-growing company. Its £73 million 2010 revenues were up 300 per cent on the year before. Profit in 2010 was £14 million. Last year, it won the Sunday Times TechTrack100.

"I sensed it would be this big," says 42-year-old Damelin, who founded Wonga with fellow entrepreneur, Jonty Hurwitz.

"We didn't want to solve a small problem but something that was a very real issue for people. In my opinion that's the only way to do it, says Mr Damelin."

Errol Damelin

Age: 42
Job: Co-founder and chief executive of Wonga
Born: South Africa
Lives: North London
Enjoys: Marathon running, mountain biking, kayaking, skiing and 'breaking the mould'

Wonga provides small cash advances to hundreds of thousands of UK consumers. It uses sophisticated risk and decision-making technology leading to computerised lending decisions, transferring cash to approved applicants within 15 minutes.

Customers can first determine the exact size and length of the loan required, using two sliders on the Wonga home page - up to £400 on a first loan and £1,000 for returning customers. They can see the loan period in days - the maximum is a month - calculating the cost in pounds and pence as the slider moves along. The site also shows the headline-grabbing annual percentage rate (APR) of 4,214 per cent. A £200 loan for 14 days would cost £33.88. Miss the repayment and Wonga charges a £20 penalty and adds just under one per cent interest a day on to your account for a maximum of 60 days. The average first-time loan is £160 and the average length is 16/17 days.

Wonga, which has issued more than three million loans - mainly to males aged between 22 and 40 - has brought a disruptive technology to the Facebook generation. "It is about breaking the mould," says Mr Damelin, an experienced entrepreneur. "It is about disrupting the status quo, enabling people to manage their cash flow without the need for long-term credit-card dependency or large overdraft fees.

"We are competing with banks and institutions that are hundreds of years old, massively powerful and commercially successful." And he is certainly relishing the challenge. "Facebook has the same problem. It competes with Google. Amazon has to compete with Walmart and Apple has to compete with Microsoft and IBM."

A former investment banker, Mr Damelin has spearheaded two previous successful start-ups; one steel, one software, but Wonga is by far his most ambitious. He has secured £93 million worth of investment from leading VCs including Greylock, Accel and the Wellcome Trust. There are plans to expand overseas this year.

So far so good, then, for Errol Damelin, who has been named Entrepreneur of the Year at the UK's Growing Business Awards, the Guardian's Entrepreneur of the Year, Founder of the Year at the TechCrunch Europas, Ernst & Young Entrepreneur of the Year for London and Digital Entrepreneur of the Year. Some might disagree.

Wonga has come under fire from commentators who deem it to be exploiting the poor and, more recently, students. It has been labelled a "loan shark." Is Mr Damelin bothered? Not really. "It's thoughtless," he counters. "We knew it would be controversial because people have preconceived notions. Everyone at Wonga believes in the ethics of the business and we are totally comfortable with it."

But is it not fuelling debt? "A vast majority of people don't take on more debt because they are sold it. I don't believe someone takes on a mortgage because they are sold one. They do so because they want a house. It's the same with Wonga. They have a cash-flow challenge and need a solution. We are not asking them to take credit they don't need." He continues: "You don't generally get sold things on the internet. You have to go and search for something. It's not the same as someone coming to your door and selling you something that you may or may not need."

In fact, Mr Damelin believes his company is performing a valuable social function. "Credit in consumer society is absolutely critical. Without it, you have no social mobility. Not having credit will increase the gap between the rich and the poor. Wealthy people will stay wealthy and be able to buy things ahead of the curve. The opportunities that arise from having cash are massive: buying a home, a car, going to university and having better work options.

"I would argue that there isn't enough social mobility in the UK. And it isn't just about credit. It's about being able to consume and invest. If people are consuming or investing wisely and using credit in an educated way to do so then I have no problem with that.

"Not having credit will have serious social knock-on consequences. What we need to do is build safe, transparent tools, not take credit away."

The company prides itself on "responsible lending." It has a strict selection process declining two thirds of applications. Customers must have a full debit card, mobile phone, steady income and reasonably good credit rating.

Mr Damelin grew up in South Africa where he studied at the University of Cape Town. He holds a masters degree from Boston University's School of Management. He moved to Israel and in 1995 became an early-stage corporate-finance banker at leading investment banking boutique YLR Investment Management, now part of the IDB group, the largest holding company in Israel.

Three years later, he was part of the founding team at steel-production firm Barzelan where he spent two years. He moved to the UK in 1999 and founded software company Supply Chain Connect Ltd the following year. It became a global leader servicing over 250 blue-chip customers and was bought by ChemConnect in 2005. It was during his time there that he says he got a sense of how powerful internet technology could be.

Now based in London, Mr Damelin says Britain has a lot to learn from other nations, particularly Israel, when it comes to entrepreneurship.

"The UK is lagging behind in terms of start-ups per capita. It isn't because there aren't good people here, problems worth solving, or a lack of capital; it's because entrepreneurship and breaking the mould isn't celebrated like it is in other places. The media and government could do so much more to create an environment where people view being an entrepreneur as a viable and attractive alternative to a regular employed job. The gap between the UK and other countries gets bigger and bigger.

"London should be one of the entrepreneurial hubs of the world."

Wonga has offices in five countries and employs close to 250 people; around 60 are based in the London office near Regent's Park.

"Being an entrepreneur is about the process of taking an idea and making it real. Walking into the office every day is a reflection of reality. It's one of the most satisfying things." As is hearing the company's catchy advertising jingle. "It's totally weird but brilliant."

Wonga has led an aggressive advertising campaign despite, says Mr Damelin, "not allocating huge budgets to it." This has helped the company become a household name. It sponsors Championship football club Blackpool and Scottish team Hearts in addition to ESPN's coverage of the FA Cup.

"Sponsorships are generally a long-term proposition and we are building a long-term business, not one of those businesses that get flipped to anybody."No plans to sell, then? No. "We are building something very special."

Not content with chasing profits, Errol Damelin recently completed the Antarctic Ice Marathon raising over $70,000 for the charity, Water.