Formula One's governing body says it will sue champions Ferrari and other teams for planning a breakaway series.
Eight Formula One teams announced on Thursday they are starting preparations for their own championship after talks with the FIA over the 2010 rules broke down.
The governing body says it will continue with its own preparations for next year's championship but publication of the final entry list, due this weekend, is now on hold pending the legal action.
The FIA maintains that Ferrari and the two Red Bull teams have pre-existing contracts to compete in their championship next year and registered them as unconditional entrants in an earlier list.
Ferrari have argued that contract no longer applies because the FIA has not respected its right to veto the technical regulations.
The breakaway group which consists of McLaren-Mercedes, BMW Sauber, Renault, Toyota, Brawn GP, Ferrari, Red Bull and Toro Rosso - have rejected FIA plans to introduce rule changes including a budget cap from next year.
They say the series will encourage new entrants, a single set of rules, and lower admission prices.
Williams and Force India have accepted the new framework, along with the three new teams.
