Sebastien Bourdais has admitted that he could be faced with a 'very difficult decision' as he waits to discover whether or not he will remain with the Toro Rosso team for a second season in Formula One.

The Frenchman finally made the step into F1 this season after a number of false dawns, but found himself overshadowed somewhat by young team-mate Sebastian Vettel - who emerged as a regular contender for points and took a stunning win in the Italian Grand Prix at Monza.

Bourdais himself struggled to acclimatise to the new STR3 introduced in the Monaco Grand Prix, but saw his performances improve towards the end of the season as his confidence in the car increased.

With Vettel having moved on to the senior Red Bull team for 2009, Toro Rosso finds itself with two vacant seats for next season but has yet to make any firm decision on who will fill them.

Both Takuma Sato and Sebastien Buemi tested alongside Bourdais at Barcelona this week as the team evaluates its options for the new campaign but Bourdais denied it was a shootout situation, and indeed admitted that who gets the drives could come down to finances - which could leave him on the outside looking in.

"It's not a shoot-out," he said in an interview with the official Formula One website. "I am here as a reference to the team because they know me quite well, and whatever they are trying, in the end it is mainly tyre comparison stuff, tyre usage.

"You obviously run the 2008 car with 2009 downforce, but that's far more effective than the (actual) '09 car because it is the same downforce, yes, but quite a bit less drag. So it will produce some quite impressive lap times, but they have got nothing to do with the 2009 car - not yet, at least.

"I am not here for a shoot-out. The problem is purely financial. The team needs some money and I think until they find a driver package which is fast enough and has got the funds - or they find a solution themselves - they won't find a solution for their line-up."

Despite inking a three-year deal with Toro Rosso when he made the move over from the Champ Car World Series, Bourdais admitted he wasn't sure if he would stay on for a second year even if the team has already said it would keen to ensure it doesn't have to change both drivers ahead of 2009.

"Absolutely not at all," he said when asked how sure he is of his future. "As far as I am concerned I don't see a decision being made any time soon because I don't see anybody being able to guarantee money right now, or tomorrow or the next day. I think it will drag on for quite some time and I am a professional driver and at some point I will need to make sure that I have a job for next year. And when the time comes I will have to make a decision.

"It was not a one-year contract [signed with STR], it was a three-year deal, obviously with options. And in the end it does not matter whether you have a three-year deal or not - there is always a line in the contract which says that if they are not happy with you they can get rid of you. The fact is that there is no such thing as a sure deal in racing, whether it is Formula One or any other series. As long as it works it's good for everyone and then it is all rosy, but if it doesn't work out as expected, then ciao! That's the way it is.

"If nobody is able to assemble enough solid funding I guess - from what [team principal] Franz [Tost] is saying - I am number one on the list because to change two drivers in a team is always a tough thing to do, and that is not their preferred solution, for sure.

"Actually Franz wanted to keep both Sebastian and me, but obviously Sebastian has moved on to Red Bull and I don't have the money, so this makes things quite difficult..."

Bourdais added that with his current focus being to retain his F1 slot, there was no 'Plan B' if the drive with Toro Rosso didn't materialise - admitting that the lack of certainty over his future was scary.

"As far as I am concerned right now my priority is to stay here, but at some point I will have to make up my mind and take a potentially very difficult decision," he said. "In the meantime it is scary because I don't know what I'll be doing next year."