FIA president Max Mosley has repeated his claim that Formula One needs to seriously consider slashing the amount of money it is spending if it is to survive as the top flight of world motorsport.

Speaking in an interview with the BBC, Mosley gave those involved in F1 two years to achieve drastic cost-cutting measures, pointing out that the economic crisis rampaging around the globe was only making matters worse for a sport already renowned as a heavy spender.

On a day when the World Motor Sport Council was due to re-examine the debate over the use of 'customer cars' in Formula One, Mosley admitted that he feared for the future of some of the category's smaller teams, as the cost of competing continued to rise, seemingly out of control as the major manufacturers sought a winning edge.

"It has become apparent, long before the current difficulties, that Formula One was unsustainable," the president said, "It really is a very serious situation. If we can't get this done for 2010, we will be in serious difficulty. At the moment, we've got 20 cars but, if we lost two teams, we'd have 16; three teams, 14. It then would cease to be a credible grid.

"It depends, at the moment, on millionaires - or billionaires, as we don't have millionaires now - subsidising it, people like Vijay Mallya or Dietrich Mateschitz. Without them, those [smaller] teams wouldn't be there."

With three races to go in a season that has already seen one team, Super Aguri, go to the wall after being unable to raise the finance it needed not only to race, but to survive on a day-to-day basis, Mosley warned that it would not be long before the biggest teams, and the manufacturers behind them, felt pressure to cut back - or, worse still in the case of the manufacturers, to pull the plug on their F1 activities completely.

"The days when [the teams] could just toss out E100m, E200m, E400m a year - which is what Formula One costs those big companies - are finished," he insisted,

Toyota, the only team currently on the grid without an F1 win in its history, is rumoured to spend more than E400m a year, and its rivals at the front of the grid continue to throw money at minor developments that they believe could give them an edge. Although this season has seen seven different winners, only two teams realistically head to the grid with the expectation of taking the chequered flag, with the rest hoping for a lucky break in order to succeed.

Mosley has repeatedly called for the sport to cut costs, and has implemented measures such as multi-use engines and gearboxes, as well as imposing a freeze on engine development, in an effort to contain the teams, but insists that there are other areas where major savings could be made. He is now expected to engage in 'do or die' talks with the recently-formed Formula One Teams Association to hammer home his message.

"We've got various means of making sure they don't spend that money, but it does mean some draconian changes," he said of his calls for the teams to come up with cost-cutting measures of their own, "Even those big spenders, if they are given the opportunity to save E100 or E200m a year will do so."

The president added that he remained keen to limit 'drive-train' development, possibly to the extent of introducing a standard package for all teams.

"If you can believe this, the engine and gearbox together - for an independent team - is upwards of E30m a year," he pointed out, "That could be done for probably five percent of that cost without the person in the grandstand noticing any difference at all."

The FIA has said that, if the teams cannot come up with credible cost-cutting measures, it would be prepared to enforce its own methods, with or without the approval of those taking part.

The WMSC confirmed on Tuesday that it unanimously agreed to give Mosley the authority to negotiate with FOTA over the introduction of radical measures to achieve a substantial reduction of costs in the championship from 2010 and, if they fail to reach an agreement, has confirmed that the FIA will enforce the necessary measures to achieve its goal.

It was also unanimously agreed to allow the teams a chance to equalise engine performance across the field for 2009, pending the introduction of cost-saving measures from 2010.