The FIA's unofficial demand that new teams sign engine supply contracts with Cosworth was "highly irregular", Prodrive's David Richards has agreed.
Another unsuccessful 2010 team applicant, the Serbian company AMCO, has complained formally to the European Commission, arguing that the Cosworth stipulation broke anti-competition laws.
Prodrive was presumably rejected on the basis that it had lined up a technical collaboration with McLaren-Mercedes.
"In any case, I consider it to be highly irregular," Richards, referring to the FIA's Cosworth stipulation, said in an interview with motorsport-magazin.com.
"I don't think it is at all appropriate for the sport's governing body to say that sort of thing," he added.
He said Prodrive was otherwise ready to make the move into F1. "I'm fairly certain that we were the only team who could prove to the FIA that it had 40 million (pounds sterling) in a bank account and was therefore ready for the off."
Richards hinted that he could get a Prodrive team on the 2010 grid at short notice if customer cars and components were allowed.