BMW Sauber is making a fresh push to get the approval it needs to become the 14th team in Formula 1 next year - despite rival Williams blocking plans to allow the grid to expand.
The Hinwil-based team, which will have new owners next year following the withdrawal of BMW from F1, does not yet have a guaranteed slot for 2010.
Its hopes of remaining in F1 rest on either one of the new teams failing to make the grade or on the unanimous approval of other outfits to expand the field to 28 cars.
The latter scenario appeared to have been ruled out at the Japanese Grand Prix when Frank Williams made it clear he would not support any move to allow an extra team in F1.
Despite that blow, BMW motorsport director Mario Theissen revealed in Brazil that negotiations are still ongoing with the FIA and Formula One Management about finding a deal - and he is hopeful Williams' position can be turned around.
"We are in discussions now - we means the future owner, plus Peter Sauber is involved, with the FIA and FOM in order to get a place on the grid," said Theissen at Interlagos. "That is all I can say at the moment.
"Currently we are talking about the 14th position... and the regulations say it needs unanimous support. "
When asked by AUTOSPORT if he believes the team could convince Williams to stop its veto on the plans, Theissen said: "Let's say, I would not understand if Frank really keeps his position as the only opponent.
"F1 needs to get back to proper business and every team sometimes needs support from the other teams, and it will be the other way around as well."
Although there is no firm deadline for BMW Sauber to resolve the issues relating to the extra grid slot, Theissen confessed that the situation was making planning for the future hard.
"There is no strict deadline but apparently it makes life difficult not to have the grid position because the team has to talk to drivers, to sponsors, and without a grid position you cannot really do a deal," he said.
"We expect to be on the grid one way or the other. Plan A would be as a 13th team and Plan B as a 14th team."