F1 CEO Bernie Ecclestone has said he does not expect two of the new teams - US F1 and Campos - to be on the grid in 2010.
Four new teams have been granted entry to next year's championship, but Ecclestone told The Times he thought US F1 and Campos would not be in a position to race by the start of the season.
"I think the people we expected to perform will and those that we thought wouldn't, won't," he told the paper.
There has been speculation for some time that US F1 would not be ready in time, as the team has remained relatively quiet since the FIA granted it a place in F1 2010. The team still hasn't confirmed its drivers, but has paid the US$440,000 entry fee to race next year.
Campos has signed Bruno Senna as a driver for 2010 and has been in talks with a number of other drivers. However, it has made clear that it does not have the resources to pay big money. Its chassis is being manufactured by Dallara and has already passed two of the FIA's mandatory crash tests, suggesting it is well on the way to being ready.
Ecclestone told the paper he thought 24 cars would be on the grid at the start of the season. With US F1 and Campos there would be a total of 26 cars in Formula One, indicating that Ecclestone thinks another new team could take the place of the two he expects to leave.