Peter Sauber believes that contemporary Formula 1's biggest challenge in the future is to cut costs.
Sauber, who this year stood down as team principal of the outfit that carries his name, insists a budget cap is needed in order to tackle the problem.
"I think the biggest challenge today is the commercial part," Sauber said according to Autosport.
"That's not only for Sauber, that's also for some of the big teams.
"Formula 1 is too expensive today, that's the important fact."
The FIA, Bernie Ecclestone and the various constructors have been locked in discussion about cost-cutting measures throughout the past season and all parties consider coming up with a solution to the problem a priority, but Sauber believes progress is not being made quickly enough and has called on the bigger teams to step up their efforts.
"The progress has been slower than slow," he said.
"It's difficult and I hope that the big teams realise that they have to do something."
In 2009, then-FIA president Max Mosley proposed a £30 million cap, though this was soon raised to £40 million before being abandoned altogether.
"We very much support a budget cap," Sauber team principal Monisha Kaltenborn said earlier in the season.
"That is the right way we should be going and we should eventually reach the point where we have a budget cap."
