Heather Mills was fired from US TV show 'Celebrity Apprentice' before filming even began.

The former model - the ex-wife of Sir Paul McCartney - was given the push by bosses at network NBC after she demanded a clause in her contract which guaranteed her a place in the final, no matter how successful she was in the rest of the show.

A source told Britain's The Sun newspapers: "Her demands were ludicrous and it soon became clear that getting her involved would be a headache.

"It was the final straw when she said she wouldn't take part unless she was guaranteed a place in the final - even after it was explained that wasn't how the show worked.

"She was politely informed that NBC wouldn't be following up their interest in her appearing."

Producers were initially keen to sign Heather as they thought her participation would be a ratings winner for the programme - which sees a group of celebrities compete in a series of business-related tasks to impress billionaire tycoon Donald Trump.

Meanwhile, Heather is planning to write a novel about a model and a rock star in an attempt to get revenge on Paul.

Heather was issued with a gagging order to prevent her discussing intimate details of her relationship with The Beatles legend as part of the conditions to her receiving her 53 million AUD divorce settlement.

The 40-year-old blonde believes writing the fictional book, inspired by her marriage, will allow her to work round the clause.

Her agents are seeking a 2.2 million AUD advance from publishers for the tome.

A source told a British newspaper: "The novel is about a model who marries the most famous rock star in the world. "She will be marketing it as a work of fiction, but it doesn't take a genius to realise what is really behind this book.

"What infuriated Heather most about the divorce was that she was gagged from telling her side of the story. This is her way of getting the information out there."