Speculation that the touted rules revolution for 2017 could be called off at the eleventh hour are being played down on all sides.

Amid suggestions in Bahrain that eight of the 11 teams are in fact now opposed, FIA president Jean Todt insisted that the April 30 decision deadline will be met.

Two of the three teams still in favour are Red Bull-owned Red Bull Racing and Toro Rosso, with the latter's boss Franz Tost saying that deferring is no longer an option.

"To come now and say 'This is not good' is too late - because [the 2017 car blueprint] has been defined."

The other team still in favour is McLaren, who came up with the basic blueprint of the 'compromise' rules - halfway between the original ultra-fast concept and what will now form the basis of the cars for 2017.

"It is not carried as far as we would have liked - it's a compromise solution - so let's see," Red Bull's Christian Horner told the official F1 website. "It is better than standing still."

Still, with the strategy group split into three voting blocks - the teams, FOM and the FIA - there remains some lingering uncertainty.

"I think I should have applied 'hopefully' to both," said Williams deputy Claire Williams, when speaking about not only the 2017 chassis rules but also changes to the power unit regulations.

"We have a strategy group meeting that's just been scheduled coming up, and as we all know in Formula 1, things are fluid. I said 'hopefully' just to temper it. I don't think you should put too much emphasis on that word."

Asked if there is a chance that the strategy group will shoot down the 2017 plans altogether, Williams answered: "I doubt it. I think it's becoming far too late in the day.

"I think we pushed the date anyway and we need to get these signed off if we're all to be ready for 2017."

The 2016 season continues with the Chinese Grand Prix next weekend.