Don't insult Simon Cowell - anywhere in the solar system

'X Factor' contestants forced to promise not to criticise Cowell, wherever they are

For the contestants vying for the title of The X Factor winner, the reality show always promised nationwide fame, chart success and a £1m record deal.

But yesterday, it emerged that the lucky singer who will be crowned this weekend will have to make do with fame over fortune. The winner will be rewarded not with a £1m cash prize but the more diminutive advance of £150,000 for a first album. The only chance of hitting the £1m mark would be after making at least four albums, a leaked copy of the contract – which is enforceable "anywhere in the world and solar system" – showed.

The contract also contains a clause protecting Simon Cowell, stating that artists must not make any statement which "may be considered unduly negative, critical or derogatory of the company – including its personnel and, in particular, Simon Cowell".

Sony BMG confirmed that the80-page contract which all finalists had to sign before the Saturday night live shows began, clearly states a £150,000 advance for the winner. But the record company added that was a standard agreement for new acts.

Critics suggested it was misleading for the show's presenter, Dermot O'Leary, to allude to the £1m deal in front of the 13 million viewers.

But Sony said the £1m had always referred to the overall value of the deal. "The prize for winning The X Factor is a recording contract with Sony BMG. The value of recording an album can be around or in some cases, far in excess of £1m and The X Factor contract is a standard recording contract."

The £1m headline figure is calculated after taking into account location costs, filming, costumes, marketing and enlisting some of the music industry's best known producers. A source from Sony BMG said: "It's enormously expensive. Some people have flown to LA to record with top producers. We have photo-shoots, wardrobe costs, travel, production costs, vocal training, sound costs every time someone does a TV appearance."

The winner gets 15 per cent from single and album sales. Headlining a tour brings 7.5 per cent of show profits and 15 per cent of merchandise sales.

The 12 contestants are given three weeks to peruse and sign the contract before the beginning of each series and offered a choice of three independent solicitors, whose fees are paid by Cowell, The X Factor creator.

Artists who are voted out of the show are still under contract to Cowell's label for up to three months.

But Sony said that left artists free to collect profits from live appearances as well as TV and corporate events.

The winner has to sign up with the agent, Modest Management, in a deal having the potential to last 14 years.

The record label has "final say" over tracks for albums, and can choose producers and single releases.

Another clause states that artists leaving the show may have to give 5 per cent of all future live earnings to Cowell for a year.