The F1 teams' alliance FOTA will meet later on Wednesday, as the May 29 deadline for official 2010 entries looms.
We reported on Tuesday that, because the series of get-togethers at Monaco last weekend netted no concrete result, the scene of the next meeting would be London.
Williams has already broken ranks and lodged its paperwork to compete next year, and the move - that could lead to fellow independents McLaren, Brawn and Force India following suit - is understood to have angered other FOTA teams.
Prospective entries USF1 and Campos Racing have also signed up, and Ferrari derisively suggested last week that more of the same would make a name change from formula one to Formula GP3 "more appropriate".
FOTA sent a letter to Max Mosley on the day of the Monaco grand prix.
"We decided to indicate to president Mosley the points that still must be clarified," Renault boss Flavio Briatore is quoted as saying by Spain's El Mundo newspaper.
"The important thing is that it was signed by the representatives of all the teams; I hope Max Mosley realises this, our unity. We will see what happens," he added.