As the F1 crisis nears its zenith, Bernie Ecclestone has warned rebel teams that crossing him could cost them "hundreds of millions of pounds".

As the F1 crisis nears its zenith, Bernie Ecclestone has warned rebel teams that crossing him could cost them "hundreds of millions of pounds".

The eight FOTA teams are openly threatening to leave the FIA-sanctioned championship and set up a breakaway series, and are believed to have told Max Mosley on Tuesday that they are not going to simply take his advice and drop the conditions attached to their 2010 entries.

The formula one teams association's official response to Mosley's letter of this week was not leaked, but the fact the sides are still talking was interpreted by some as a position sign.

An FIA spokesman said: "The FIA has received a letter and various attachments from FOTA, the contents of which are not entirely negative, and we are currently examining the details."

Another positive sign is the rumour that, on Friday, the FIA will publish an entry list bearing the names of five teams: Williams, Force India, and only three new entries despite the multiple applications.

That would leave space and time for the eight FOTA teams to reach a compromise with the FIA president and be added to a later edition of the entry list.

However, it has been suggested that Friday's list could also feature Ferrari, Red Bull and Toro Rosso, who are all understood to have in the past signed agreements committing to the sport, including in 2010.

An FIA source confirmed that, in addition to the FOTA letter, a separate letter from Mosley was sent this week to Ferrari. But the Italian team's boss Stefano Domenicali does not think Ferrari is bound to race in F1 next year.

"We had an agreement with the FIA, but we felt that the obligations inside that agreement were breached, so the agreement is not valid any more," he said.

The uncertainty is unnerving everyone. In the Daily Express, F1 chief executive Ecclestone nailed his colours to the FIA by warning contracted teams against betraying him in the form of a rival series.

"Apart from my contracts with teams, if somebody went to any of our contracted people, companies, television contractors, we would view it very seriously.

"Any action could run to hundreds of millions of pounds, who knows how much?" he added.

Again playing a conciliatory role is the post-Ron Dennis management of McLaren, with new boss Martin Whitmarsh commenting to the German press on Tuesday.

"Unfortunately the teams, the FIA and the rights holders do not always share opinions, but it would be wrong to tear up everything built up in the past 60 years," he said.

"This is a sport with a lot of very strong personalities involved. Perhaps after so long some parties think they don't need the other any more. But if we leave personal considerations aside, a compromise is possible," the Briton added.