By Andrew Benson
Formula One chief Bernie Ecclestone has ramped up the pressure on Silverstone yet again with his imposition of a deadline for the track to raise money for improvements.
And the intruder on the track during Sunday's British Grand Prix has raised further doubts about the safety of the event on the Formula One calendar.
But how serious is the threat to the race? And what are the main issues involved?
Do people really believe Ecclestone would dump his home race from the F1 calendar?
F1 team owner Frank Williams does not. "It's one of the homes of F1," Williams has said. "I think Bernie is very sensitive to that. He's an Englishman himself."
And certainly some believe Ecclestone is using the threat of dropping the race to force Silverstone out of what until 2000 had been a distinct lethargy about upgrading its facilities.
On top of that, Silverstone has a contract until well into the next decade, and the circuit meets all F1's standards, so it is difficult to see how it could be dropped.
But not everyone is so sure.
There are continuing rumours that Ecclestone wants to irreparably damage Silverstone's owner the British Racing Drivers' Club so he can take over the track himself. And some BRDC bosses will admit privately that this is one of their fears as well.
Some even believe the Silverstone row is tied up with the threat by some of the F1 car manufacturers to set up a breakaway championship in 2008.
Many of the leading figures on Silverstone's side are also linked strongly to teams in the GPWC, the organisation making the breakaway threat - including McLaren boss Ron Dennis, Frank Williams and Jackie Stewart, a consultant for Jaguar and also the BRDC president.
What does Ecclestone say?
Nothing on the GPWC. But he denies wanting to own Silverstone. "I have never wanted to get control of any [F1] races. I don't care who is in control," he told this website earlier this year.
But Ecclestone already does control some races so, as usual, his real plans are shrouded in mystery.
What does Ecclestone want Silverstone to do?
Silverstone has already vastly improved road access to the track at the demand of F1's governing body the FIA after the catastrophe of the 2000 event, when torrential rain caused chaos, including five-hour traffic jams around the track.
The next stage of the improvements, which are part of the track's contract with Ecclestone to hold the race, is a revamped version of the current pit and paddock complex and media centre.
Ideally, however, Silverstone and Ecclestone want the pits moved from their existing position to Hangar Straight and housed in a brand new, state-of-the-art building.
Does Silverstone have a problem with that?
In theory, no. It can afford to upgrade the existing paddock. However, the track needs to raise money to be able to fund what it calls the "dream scenario" of the re-sited pits.
Ecclestone has demanded Silverstone's owner the BRDC borrows £40m from banks to add to the £13m he says is already in its "kitty".
But the BRDC, a not-for-profit organisation, says a loan like that would be "ridiculous" as it already has an overdraft of £3.26m.
Hasn't Silverstone already done a lot of work?
Yes, but Ecclestone says he wants it to be the best F1 facility in the world.
Isn't that a bit unfair considering that other tracks are funded by local or national governments and there are plenty of circuits in worse condition than Silverstone?
The BRDC certainly thinks so.
Brazil's Interlagos track is always singled out as an Ecclestone favourite that is in far worse condition than Silverstone.
Ecclestone recently acknowledged that Interlagos has problems, but said: "That's Brazil, and Silverstone is in Britain. We are supposed to be the best in this country and this should be the best Grand Prix in the world."
Why is it difficult for Silverstone to raise money?
It is being compared with tracks like Sepang in Malaysia, which is funded by the national government, and Indianapolis in the US, which is owned by the multi-billionaire Tony George.
But Silverstone has to get by on the money it can raise through its events, which it also needs to invest in the future of British motorsport.
There have been hints from the British government in recent days that it will help Silverstone out to some degree.
This could be done on the basis that without a blue riband event like the Grand Prix, the £5bn motorsport industry would suffer.
But still the government is in a difficult position. With so much criticism of the country's schools, hospitals and transport infrastructure, it can hardly fork out countless millions to help out a race track.
Was the intruder on the track during the Grand Prix on Sunday a threat to the future of the race?
The fear after the race was that Ecclestone and FIA president Max Mosley would use the security lapse as a stick with which to beat Silverstone. Ecclestone has denied this, but his words will be cold comfort to BRDC bosses, who are well aware of his capricious nature.
Are F1 bosses still upset about traffic problems at Silverstone?
No. There were isolated problems at the weekend, and signage could also be better, but traffic flow around Silverstone is much improved.
An FIA spokesman told this website: "Overall, in terms of traffic management, it seemed to work very well. There are areas that we would look to see them improve, and they would share that view. But I think the substantive work has been done."