The Silverstone circuit is like the heart of F1 around it are various of the works factories of many teams not just those that play our National Anthem when they win the constructors prize at a Grand Prix and with them are many of the makers of parts. If Bernie Ecclestone had followed through on his veiled threat that he didn't need there to be a British Grand Prix there might very well have been ramifications for employment.
However, last night Bernie seemed happy with the deal that was presented by the Silverstone owners. He was irratated with the length of time it took him to come to a deal though saying:
"It's been a long and tiring nonsense. They could have done this whole thing months and months ago."
But maybe from their long experience of dealing with the billionaire the circuit cheifs wanted to build in a little security if they stepped up to become the saviour of the British GP. Having aparently settled on a 10 year deal it would appear that they have got that little bit of security to make investing in improving the facilities
Update: This has now been confirmed with a 17 year deal agreed.