The Formula One Teams' Association (FOTA) walked out of a technical meeting with the FIA about future rules on Wednesday, renewing doubts about the strength of the recent peace deal.
The FIA held one of its regular Technical Working Group meetings at the Nurburgring to make moves on finalising F1 rules, following agreement to scrap controversial budget cap regulations.
The meeting included representatives from all the current teams, plus new outfits US F1, Campos Meta and Manor Grand Prix.
Some progress was made in terms of agreeing to scrap the specific budget cap rules introduced on April 29.
However, the teams could not agree on a minimum weight limit for 2010, and there had also not been a sign-off of the legally binding agreement to reduce costs.
Of most interest, though, just a day after AUTOSPORT revealed that FOTA had been told that it could not finalise rules without agreement from non-member teams, the eight outfits involved in the organisation left the meeting when asked to provide input on further rule changes it hoped to see in place.
A statement from the FIA, detailing the meeting, said: "Following the decision of the World Council on 24 June to revert to the pre-29 April version of the 2010 F1 Sporting and Technical Regulations, the FIA today met the teams which have entered the 2010 Championship to seek their agreement to these changes.
"All changes have now been agreed subject only to the maintenance of the minimum weight at 620 kg and the signing of a legally binding agreement between all the teams competing in 2010 to reduce costs to the level of the early 1990s within two years, as promised by the FOTA representative in Paris on 24 June.
"The eight FOTA teams were invited to attend the meeting to discuss their further proposals for 2010. Unfortunately no discussion was possible because FOTA walked out of the meeting."
The decision by FOTA to walk out of the meeting has not yet been explained, but it has renewed fears that there is still major differences about its path for the future and the FIA's.
Mosley has already told FOTA that he is considering standing again as president in October in light of what he believes were deliberately misleading comments made to the media about a deal they reached last month to avert the threat of a breakaway.