Ecclestone had likened the running of Silverstone's blue-riband event to a "country fair" after getting lost on his way to the circuit on race morning.

At the time he refused to say that Silverstone's place on the F1 calendar was secure because it has a contract - which runs until 2010.

But on Wednesday Ecclestone told BBC Radio Five Live that the race was safe: "It's got a contract for the next 10 years. There's no threat."

Ecclestone reiterated his criticisms of the organisation of the event - and said that he discovered the problems because his helicopter was unable to land.

"I was lucky to have a helicopter ride because it meant when there was a problem I told my driver to go all the way around the circuit and I could see for myself," Ecclestone said.

"There were people standing in the road. They had hot-dog stands along the roads blocking vehicles and pedestrians.

"It was totally disorganised - and organisation costs nothing."

Asked about his criticism of signage around the track, Ecclestone said: "We give designs for signs to all the races and everyone else uses them."

He also cast doubt on the ability of the race promoters, Octagon Motorsports, to make the event pay in the long term.

Octagon has done a deal to lease Silverstone from its owner the British Racing Drivers Club (BRDC) for the Grand Prix for the next 10 years.

It pays Ecclestone's companies �10m per year plus interest and an annual fee of �6m to the BRDC for leasing the track.

This makes it probably the most expensive Grand Prix to run.

"Octagon has paid more than is commercially viable," Ecclestone said.

The next stage of Octagon's plans to redevelop Silverstone and bring it in line with modern Grand Prix venues is next year, when a new pit and paddock complex will be built.

Ecclestone said: "The thing is, we have a special architect which we use and we sent the designs to Silverstone, but they've chosen to do it their own way."

Max Mosley - the president of motorsport's governing body, the FIA - has also said that Silverstone is an integral part of the calendar.

"The British GP is very much one of the traditional races and provided it is properly run and properly sited then there is no realistic chance that it would be lost," Mosley told the Reuters news agency at the weekend.