While US F1 seeks approval from the FIA to miss up to four races, we understand that a major potential sponsor has given up on the team and followed the American outfit's head of business development out of the door.

Although Pitpass is unable to confirm the story - let's face it, you're unlikely to get anyone at US F1 to confirm the date - a reliable source tells us that the North Carolina outfit's ambitions have taken a major hit with the departure of the Locstein Group, a global financial services firm based in Geneva.

According to our sources, Locstein was on the verge of agreeing a £10m deal with US F1 but became increasingly concerned at the lack of progress and the fact that the team was likely to miss the season opener.

Meanwhile, US F1's head of business development, Brian Bonner, finally decided enough was enough and opted to leave the team and focus on his own company, B4 Marketing, which specialises in branding, sales and marketing support, and representation services.

Bonner, a former racer who can include the 1991 IMSA Camel GT rookie of the year and 1992 Indy 500 runner-up rookie of the year on his CV, is understood to have agreed a deal with Locstein and is now thought to be looking to place the potential deal with another team.

There remains confusion as to Youtube founder Chad Hurley's role with the American team. However, despite Anderson's assurance that he is still involved, it is believed that the departure of Bonner and Locstein might be the final straw.