By Tom Bishop BBC News entertainment reporter

Bill Bruce is among comedians taking part in Free Fringe shows

Venue charges, accommodation and promotional costs have prevented new acts from taking part, they claim.

Comic Marc Blake said: "Comedians pay huge amounts for little in return."

A festival spokeswoman said: "The Fringe can be a financial risk for performers, but something wonderful might come from it."

The Fringe is the world's largest arts festival, selling 1,251,997 tickets for acts by 15,629 performers in 236 Edinburgh venues last year.

'Next step up'

"People take a show to Edinburgh in a bid to gain work, management and good reviews," said Blake. "It's the recognised 'next step up' for new comedians."

Blake performed his daily Helmut's Half Hour show at Edinburgh venue Underbelly during last year's three-week festival.

"It cost me �4,000 to use the venue, �2,000 in management company fees and over �1,000 for accommodation and to publicise the show," he said.

"Despite gaining good reviews and big audiences, box office takings were not as high as the venue stipulated so I received no share of the profits."

Comics are paying and audiences are paying, but all the money is going into the pockets of everybody else Marc Blake

Blake said a number of other comics also lost "vast amounts of money" at the Fringe.

"It seems that comics are paying and audiences are paying, but all the money is going into the pockets of everybody else," he said.

Glasgow comic Bill Bruce said he paid the Greenside venue �600 to perform shows for a fortnight during last year's festival.

"I spent another �600 on publicity, �240 to appear in the official festival brochure and the food was expensive," he said.

Bruce said performing at the festival was "a fantastic experience" which won him numerous bookings, but he "barely broke even" on his costs.

"As a Scottish comedian based in London, it's quite ironic that it is now more expensive for me to come back to Edinburgh to do a show," he said.

This year Blake and Bruce will take part in free festival stand-up shows hosted by comedy club Laughing Horse.

Previously unknown Will Adamsdale won 2004's Perrier award

The club does not ask comics to pay to perform at its Free Fringe venues, and audiences make donations at the end of each show rather than pay a ticket fee.

"Every year the public is charged more to see each act, which makes them less willing to risk watching new comedians," said Laughing Horse spokesman Alex Petty.

The club will host 20 Free Fringe shows at its venues Canons Gait and Lindsay's.

"The whole idea of the Fringe was that anyone could just turn up and perform," said Mr Petty. "You can still do that, but you need to have a big cheque book with you."

A spokeswoman for the Fringe denied it had become too expensive for acts to take part. She said: "It's a risk that performers choose to take.

We do try to tell people when they register that they have got to be realistic with their budgets Fringe spokeswoman

"We do try to tell people when they register that they have got to be realistic with their budgets, and not to necessarily expect brilliant financial things to happen."

The spokeswoman said last year's Perrier award winner, Will Adamsdale, proved that previously unknown acts can achieve great success at the Fringe.

She said 159 festival shows were free to audiences last year, including its annual outdoor Free Sunday event and shows hosted by The Stand comedy club.

Further ticket discounts would be offered to the public at this year's festival, which begins on 7 August.

The Fringe is a very big event now and it's a big investment to come up and take part Fraser Smith, Gilded Balloon

The Gilded Balloon - a major Fringe venue alongside The Underbelly, The Pleasance and the Assembly Rooms - charges at least �8 per ticket for its festival shows.

"We charge audiences and performers at a similar level to other festival venues," said spokesman Fraser Smith.

"The Fringe has moved on from where it was 10 years ago, when you could see a show for �4 a ticket. It's a very big event now and it's a big investment to come up and take part."

While he said the Free Fringe scheme was "fantastic" and "would encourage performers", he advised acts to perform at more established venues.