Pirelli's planned changes to its controversial tyres for Canada and beyond are now under a dark cloud. Media reports, including by Marco Canseco in the Spanish sports daily Marca, say the FIA has hi...
Media reports, including by Marco Canseco in the Spanish sports daily Marca, say the FIA has hit back by insisting that mid-season changes are only allowed on the grounds of safety.
But Pirelli's Paul Hembery had announced last week that the planned changes, for Montreal and beyond, are because "the number of pitstops was too high" so far in 2013.
The FIA's opposite view is enshrined in the technical regulations.
At the very same time, Hembery hit out at teams like Red Bull and Mercedes, who have "used the media" to pile the pressure on Pirelli.
"What has changed compared to the past two years," he told German newspaper Bild am Sonntag, "is that people have used the media in order to get a benefit for themselves.
"The people who criticise make the headlines," Hembery added, "but we have been contacted by many people who are asking us not to give in to the pressure."
So after Red Bull and Mercedes complained loudly about the changes, other teams like Lotus, Ferrari and Force India - whose cars work well with the existing 2013 tyres - are hitting back just as strongly.
Lotus team owner Gerard Lopez told Welt am Sonntag newspaper that it is "stupid" that changes can be made "that punish the clever and creative teams" whilst "rewarding the losers".
"Where is the sport in that?" he quipped.
"I don't know exactly why Pirelli is making changes," Force India driver Paul di Resta is quoted by Speed Week, "but I've been told that everything is fair.
"I suspect that the changes will hurt us, Ferrari and Lotus a little bit more than the others.
"We invested a lot of time in the winter to get these tyres working, so of course these changes are a bit frustrating," he added.
Di Resta said he doubts Pirelli can justify the changes on the grounds of safety, as is required by the regulations.
"I don't think they (the tyres) are dangerous," he insisted. "People have been getting excited about the last race, but we had no problems in the race.
"I think most of the tyre failures are down to driving over debris."