Melbourne - Red Bull and Mercedes have stated that they are against more teams being added to the Formula One grid after the sport's chief suggested 12 would be better than the current 10.
FIA president Jean Todt has admitted he is keen to boost the number of teams, but is facing resistance from constructors who have witnessed several outfits come and go as they struggle with spiralling costs.
"I always go for quality over quantity. I think we've got 10 teams that are in pretty decent health at the moment, compared to previous years," Red Bull chief Christian Horner said.
"As we see when the grid has expanded (in the past), none of those teams that came in a few years ago are still here.
"In Formula One the cost of entry is so high it's virtually impossible unless you are a multi-multi billionaire, and sometimes even that's not enough," he added.