Cameron asked to block Circuit of Wales state aid
Silverstone racetrack bosses have asked David Cameron to prevent tens of millions of pounds of potentially "illegal" state aid being used for a new £280m circuit in Wales.
Developers behind the Circuit of Wales scheme in Ebbw Vale, Blaenau Gwent, are said to be asking the Welsh and UK governments to commit up to £50m.
Silverstone's MD has written to the prime minister to intervene.
Planning issues have delayed the start of work at the site.
BBC Wales business correspondent Brian Meechan explains.