Three teams in battle for 2015 survival

One, Caterham

The health of the sport's most financially struggling outfits has been under an intense spotlight since it emerged the richest teams might be asked to plug gaps on the 2015 grid by running three-car operations.

Arguably the most endangered team is Caterham, whose founder Tony Fernandes suddenly pulled the plug this year, almost leading to a total collapse before July's British Grand Prix.

The green-coloured team is now owned by a mysterious consortium of Swiss-based Dubai investors, amid continuing rumours of serious financial problems.

But Manfredi Ravetto, the new boss, insists Caterham has money to spend.

"We are currently testing our 2015 car in Cologne, at Toyota's wind tunnel," he told F1's official website. "Obviously you cannot run your car in Cologne just because of our extremely nice attitude!

"And if we do this (pay Toyota) it means that we are fully committed to being here next year," he added.

Two, Marussia

Another obviously embattled team is Caterham's fellow backmarker Marussia, but sporting boss Graeme Lowdon insists the team can also afford to keep racing.

"You don't want to give the wrong impression by glibly saying 'yes, we're fine' because it's always a challenge operating businesses in this environment," he told Sporting Life.

"(But) we have an obligation to trade correctly, and if you don't reasonably believe you can do that, you have to stop," Lowdon added.

"If we didn't think we could be here, then we wouldn't be here."

Three, Sauber

And the third current team clearly battling merely for survival is Sauber, the 21-year-old Swiss outfit whose fortunes began to fade some years ago when owner BMW pulled out.

Founder Peter Sauber and co-owner Monisha Kaltenborn are putting a brave face on the situation, but a man also with knowledge of the situation paints a more uncertain picture.

One of the men central to the oft-reported 'Russian rescue deal' is Oleg Sirotkin, whose son Sergey Sirotkin was initially believed to be a shoo-in for a race seat.

Now, the young Sirotkin's prospects are not so clear.

"In my opinion it is 50-50," Oleg Sirotkin told the Russian website f1news.ru.

"There have been a lot of problems, one of which is the unstable situation of the teams. There is no certainty they will even be at the start next season.

"For example," he revealed, "we are working closely with Sauber, but they seem to have a problem."