Sir Jackie Stewart has refused to admit defeat in the long-running battle to save the British Grand Prix.

Sir Jackie Stewart has refused to admit defeat in the long-running battle to save the British Grand Prix.

Formula One supremo Bernie Ecclestone has threatened to break off talks with the race's organisers, the British Racing Drivers Club, because of their unwillingness to meet his terms.

The Silverstone race has only been included on the 2005 calendar subject to his conditions being agreed and Ecclestone has claimed he is running out of patience with the BRDC.

The two parties have been at loggerheads since Silverstone was left off next season's provisional calendar last month but Ecclestone says he has made significant concessions on his original demands.

He says he does not intend to wait any longer and is starting to consider offers from prospective venues in other countries.

BRDC president Stewart claims Ecclestone is being unreasonable but has not given up hope of saving the race.

The former world champion Stewart said on BBC Radio Four's Today programme: "The issue is certainly still under discussion, the reasons are purely financial and the conditions Bernie Ecclestone is offering are conditions that economically are impossible.

"It is more and more expensive to put on races. No independent promoters can afford it other than governments. It is unaffordable and something which would bankrupt us.

"What we want is a two-year contract to develop Silverstone into a more modern facility but Bernie has moved away from a guarantee for this given to Sports Minister Richard Caborn."

But he added: "They say the fat lady hasn't sung yet. A lot of people take great exception to what has happened."

Ecclestone has been a fierce critic of Silverstone and its facilities for years. New circuits such as Malaysia, Bahrain and China have raised the standard and Ecclestone has consistently called for improvements at the Northamptonshire venue.

His latest argument with the BRDC began as a gripe over price but negotiations have come down to what he claims are a series of nit-picking disputes over his terms, some of which he described as "red herrings".

The BRDC, with help from Caborn, convinced Ecclestone to significantly reduce his financial demands.

But Ecclestone told the BRDC that his offer was for one year, with a six-year option, while the club are pressing for two years initially, with the further option of five years.

Ecclestone said in a Daily Express interview: "You cannot keep trying to sell something to people who don't want to buy - it is a fact of business.

"As we have been unable to reach agreement on the length of the commitment or the financial terms, we have to admit defeat and the end of discussions.

"I have a country knocking down my door for a race who are prepared to invest hundreds of millions of dollars to build a state-of-the-art circuit for F1 in the 21st century, and make a guaranteed commitment to pay substantially more that we have agreed to accept from the BRDC.

"I can't make a sensible business case for turning them down in order to give the BRDC a two-year deal at a significant discount, which they want while they try to make up their minds what they want to do."

He claims he has done his best to maintain a race which has been on the world championship roster but his latest comments would appear to mark a telling blow to its survival hopes.

"As much as I would like to have a British Grand Prix, I have done more than I have for any other race in the world to try to keep it on," Ecclestone added in The Times.

"But I cannot make a deal without the other side and I have to move on."

Ecclestone has not yet identified the countries hoping to break onto the F1 calendar, although a Turkish race was included on the provisional 2005 schedule for the first time last week.

It has been mooted that the United States could stage a second race in years to come, while London remains a future option.