The USF1 team’s future was cast in doubt after financial services group, Locstein, withdrew its sponsorship yesterday.

A lack of sponsorship money for the team has resulted in work grinding to a halt and several members of the workforce quitting, leaving just 60 on hand. There are also rumours that several other sponsors, including YouTube owner Chad Hurley, have threatened to leave the team.

“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 USF1,” an official statement read.

Earlier this week the team’s co-founder, Ken Anderson, asked for the FIA’s permission to miss the first four races of the 2010 season following slow car development. USF1 had fallen behind in modelling their chassis, and decided to cancel their crash testing before their first race at Bahrain.

New team member Jose Maria Lopez could also be leaving USF1 to join Spain’s Campos Meta.