THE British Grand Prix could be rubbed off the Formula One calendar after Silverstone's owners triggered a break clause in their contract.

The British Racing Drivers' Club, who own the Northamptonshire circuit, gave notice of their intent to leave their current deal in 2019, after revealing losses of almost £8million over the last two years.

Nearly 140,000 spectators watched triple world champion Lewis Hamilton claim his third consecutive win at Silverstone last year and a near sell-out crowd is expected again this weekend as Hamilton bids to reduce rival Sebastian Vettel's 20-point lead at the summit of the championship.

But the demands of Silverstone's hosting fee, which goes up by five per cent every year – from £12million in 2010, the year in which the new long-term deal started, to £16million this season and £25million in 2026 – is crippling the circuit.

The BRDC and Silverstone want to continue their relationship with Formula One but will not do so at the cost of financial ruin. The circuit, unlike many other tracks on the F1 calendar, receives no government backing.

''This decision has been taken because it is not financially viable for us to deliver the British Grand Prix under the terms of our current contract,'' said BRDC chairman John Grant.

"We sustained losses of £2.8million in 2015 and £4.8million in 2016 and we expect to lose a similar amount this year.

''We have reached the tipping point where we can no longer let our passion for the sport rule our heads. It would not only risk the very future of Silverstone and the BRDC but also the British motorsport community that depends on us.

"This situation is not sustainable – for the BRDC but also for the British Grand Prix and Silverstone. We cannot continue to sell our core assets in order to fund the Grand Prix. Put simply, we've run out of road and have been left with no option but to trigger the break clause.

''However, I want to be clear that although we have now activated the break clause, we are fully supportive of the changes the Liberty Media team are making to improve the F1 experience.

''Our hope is that an agreement can still be reached, so that we can ensure a sustainable and financially viable future for the British Grand Prix at Silverstone for many years to come.''

Liberty Media, the American conglomerate which took over the sport in January, have already staged a series of talks with both the BRDC and Silverstone.

They will not want to lose an event which has been an ever-present on the calendar since the world championship began in 1950.

But F1's new owners also chose to take aim at the timing of Silverstone's announcement with this year's race just five days away.

''The week leading up to the British Grand Prix should be a week of great celebration for F1 and Silverstone," said a Formula One spokesman.

'We deeply regret that Silverstone has chosen instead to use this week to posture and position themselves and invoke a break clause that will take effect in three years' time.

''We offered to extend the current deadlines in order to focus on everything that is great about Silverstone and Formula One. Regretfully the Silverstone management has chosen to look for a short-term advantage to benefit their position.

"Our focus is still to preserve the British Grand Prix. We will carry on negotiating with the promoter in good faith and in private to reach a fair and equitable solution.''