The future of US F1 is in further doubt following the withdrawal of a major potential sponsor.
The North Carolina-based outfit has already asked motor sport's world governing body, the FIA, about the possibility of missing the opening four races given their financial difficulties.
A lack of sponsorship money has resulted in work grinding to a halt, delays in last month's payroll and several members of the workforce quitting, leaving just 60 on hand.
To rub salt into their wounds, Geneva-based financial services group Locstein has announced it will not pursue a deal with the team in light of their current problems.
A statement read: "As a matter of course, Locstein evaluates a variety of business opportunities around the globe, including sponsorship in Formula One racing.
"Locstein did engage US F1 Team regarding sponsorship, but when it was apparent the team was not able to participate in the entire 2010 season, Locstein elected to withdraw from further involvement with US F1."
The news will serve as a bitter blow to US F1, whose key investor, YouTube co-founder Chad Hurley, was yesterday involved in talks with another of the new teams, Spanish marque Campos Meta.
Campos was last week the subject of an internal takeover by partner and president Jose Ramon Carabante, although Bernie Ecclestone is understood to have played a key role in their salvation.
Doubts, though, remain as to whether they will make the grid for the opening grand prix of the new season in 18 days' time in Bahrain as they are still searching for funds.
That could lead to driver Jose Maria Lopez, who had signed for US F1, switching to Campos as it is believed he has around £5million worth of sponsorship behind him to guarantee his drive in F1.
Whether Hurley also switches his allegiance to Campos remains to be seen, although Lopez's manager, Philip McGough, is simply hoping a deal can be done that involves the Argentinian.
"The two groups that talked will do everything possible so that 'Pechito' (Lopez) can be in Formula One," McGough told Argentina's Diario Hoy.
"Both Chad Hurley and Jose Carabante talked for several hours to find a solution for the budget issues both teams have.
"For us this merger is very important as it works in favour of Lopez racing this year.
"Right now things are in the hands of the two investing groups who have the final word."