LONDON (AFP) - Formula One supremo Bernie Ecclestone has told Silverstone's owners to accept his offer to save the British Grand Prix or drop out of the 2005 world championship.
The British GP has been given a provisional date of July 3 on next year's draft schedule but a commercial deal must be agreed before the race is confirmed.
Silverstone's owners, the British Racing Drivers' club, and Ecclestone disagree on the length of the deal.
"We can't negotiate any more on this," Ecclestone told the Daily Express.
"They are on the calendar for the moment but we have to have a decision on this soon."
The BRDC is reported to be seeking a two-year deal to stage the British Grand Prix at Silverstone, followed by talks on the following five years.
Ecclestone is believed to have offerrf a contract for next year followed by negotiations on the following six.
BRDC president Jackie Stewart said no deal had been concluded.
"We are pleased with progress so far and will continue negotiations that we hope will conclude with a financially viable British Grand Prix which in turn will help create a platform for sustainable development of Silverstone," he said.
BRDC chief executive Alex Hooton added: "We are currently considering the terms of the draft agreement provided to us by Mr Ecclestone which will need further negotiation. But we are hopeful of concluding the matter as soon as we can."
The calendar will be finalised when the FIA's world motor sport council meets on December 10.
France and San Marino were also given provisional dates by F1's governing body the FIA on Wednesday.
The promoters of the three provisional dates must conclude talks with Ecclestone by then, while the three races yet to have dates confirmed - Europe (at Germany's Nurburgring), United States and China - will also be finalised in time for the meeting.
Ecclestone is limited to 17 Grands Prix a year by contract with the teams and must trim his draft calendar of 19 if he is to avoid a costly pay-out.
This year he had a multi-million pound bill for paying the teams to race in an 18th race.