For the past few weeks there have been rumblings of unease behind the scenes following the FIA's selection of three new teams to race in F1 next year. This is hardly surprising since Manor, Campos and USF1 aren't exactly the best-known names in motorsport whereas teams like Lola and Prodrive had an F1 pedigree but were turned down.

First we heard that Alan Donnelly, the FIA president's representative, was doing PR for Manor and then, just a few days later, we learn that Donnelly had even brokered the sale of stakes in Manor weeks before it got its grid slot. Donnelly wriggled out of both accusations but mud sticks. Today's revelation is so strong that the FIA hasn't been able to deny it and it sums up everyone's worst fears about the selection process.

Writing in the Telegraph, Pitpass' business editor Chris Sylt reveals that several of the teams which failed to get grid slots next year have accused the FIA of bias. They say that during the application process the FIA insisted they had to buy engines from Cosworth in order for their bid to be accepted.

This had previously not been a condition but in fact it was a crucial one. "We were told that if we wanted to take up the 2010 grid slot we would have to sign a three-year engine contract with Cosworth." said one team boss.

In an explosive letter seen by Pitpass, another team boss said "I went to the FIA's London commission to defend our application on Thursday 11th June. It did not take me long to realise that something strange was afoot. Just before entering the meeting I was advised by Tony Purnell that for my application to have any chance of success I would need to report Cosworth as my engine supplier for three seasons. I commented that I had a real possibility of obtaining a Renault, Mercedes or Ferrari engine, however, it was made very clear to me that it was considered a 'mandatory' condition from the powers that be (Max) that Cosworth was the engine supplier."

Incredibly, this meeting, where the team boss found out this crucial condition which needed to be met in order for his bid to proceed, took place just one day before the 2010 team selection was announced by the FIA. It didn't give much time to alter plans to incorporate Cosworth which previously hadn't been known to be necessary.

Yet another source in the sport told Sylt that one hopeful team boss "said he was going to use Mercedes engines and he was told that if he wanted to be selected, he would have to use a Cosworth engine." With that old chestnut of alleged bias against Mercedes rearing its ugly head again you would have thought that the FIA would have come out with a robust denial. You'd be wrong.

Sylt put the charges to an FIA spokesman asking why it had favoured Cosworth in the process to select the F1 teams, adding that this came across as commercial bias - not what you expect from an independent governing body.

The surprising response was that "the FIA has always considered the availability of an independent supply of engines to the new Formula One entrants and the other independent teams to be a priority. Without the independent supply of F1 engines, the whole grid would be at the mercy of the car industry and no new team would be able to enter without their permission. Existing independent teams would also have to follow their instructions. An independent supply of engines is essential to a healthy Formula One."