Formula 1 is bracing itself for what could be its biggest day in recent years, with the FIA due to publish the much awaited 2010 world championship entry list before lunchtime on Friday.
After last-ditch talks aimed at bringing an end to the stand-off between the FIA and the Formula 1 Teams' Association (FOTA) ended inconclusively on Thursday afternoon, all eyes are now on how many of the current teams will be on the entry list.
FIA president Max Mosley met in London with four representatives of FOTA - Ferrari's Stefano Domenicali, Brawn GP's Ross Brawn, Red Bull Racing's Christian Horner and Toyota's John Howett - in order to try and thrash out an 11th hour deal that will keep all the current teams committed.
But although there was no public confirmation that the two sides had edged any closer to a deal, there were suggestions that FOTA and the FIA were not totally at loggerheads on a way forward.
One source compared the situation to the black or white smoke signals given off by the Vatican during the election process of a new Pope. "There is grey smoke tonight," he said.
In recent days there has been more talk of a compromise deal, with Mosley indicating in a recent letter to Ferrari president Luca di Montezemolo that the FIA would be ready to scrap the two-tier F1 plans, and sign a Concorde Agreement, if teams agreed to a 100-million-euro budget cap for 2010 - prior to it being reduced to £40 million (GBP) the following year.
As to what happens with the entry list announcement on Friday, no one outside of the FIA's circles is sure about what will happen.
Williams and Force India are certain to be on it, having lodged unconditional entries, and it should not be too difficult for the FIA to find at least three new teams to fill the available slots on the grid.
However, which of the remaining current outfits is on the entry list will determine where F1 is heading in both the next few weeks and perhaps the longer term.
Should the entries of the eight remaining FOTA members - Ferrari, McLaren, BMW Sauber, Renault, Toyota, Scuderia Toro Rosso, Red Bull Racing and Brawn - be rejected, then it could be the signal for those teams to accelerate their plans for a breakaway championship.
There would also likely be huge controversy should the FIA choose to put Ferrari, and perhaps the two Red Bull teams, on the entry list unconditionally - if the governing body stood by the belief that some teams have contractually tied themselves into racing in F1.
One way of defusing the tension, however, would be for the FIA to hand provisional entries to all of FOTA's outfit - pending the successful resolution of talks aimed at reducing costs.
Ferrari has made no secret of the fact that it will only race in F1 if it is happy with the rules - and the announcement of the entry list comes ahead of a visit to Le Mans by di Montezemolo and the Scuderia's team principal Stefano Domenicali.
In a statement issued on Thursday, di Montezemolo made a clear hint that the challenge of Le Mans would be enough to attract the Maranello team in the future.
"I am delighted to be given the opportunity to start a race that has made motor racing history and has such strong links with Ferrari," he said.
"Our Scuderia has delivered some unforgettable achievements on this circuit. The Le Mans 24 Hour Race is synonymous with technologically-advanced sporting competition and has always been a focus of great attention on our part."
The other interest in the entry list will come with which of the new outfits is granted a place on the 2010 grid. Among the leading contenders to be given the nod are Prodrive, Campos Racing, Epsilon Euskadi, Lola, Superfund, USF1 and Team Lotus.
AUTOSPORT will keep you fully up to date with news and reaction to the publication of the 2010 entry list.