May 29 (GMM) Pirelli's move to merely test rather than race its tweaked tyres in Canada is almost certainly due to the refusal of some teams to agree.

The rules state that F1's sole tyre supplier can only make changes on the grounds of safety or with the unanimous approval of every team.

But it emerged on Wednesday that, despite reportedly wanting to debut tweaked rear tyres in Canada that are less likely to delaminate, some teams almost certainly remain opposed on sporting grounds.

Kimi Raikkonen, Lotus F1 E21
Kimi Raikkonen, Lotus F1 E21

Photo by: XPB Images

The tyres, featuring a kevlar rather than a steel internal belt to reduce overheating, will now only be tested in Canada, with Pirelli hoping to debut them in the subsequent British Grand Prix.

"We will not race tyres that we have not tested first," Lotus team owner Gerard Lopez was quoted on Wednesday by Germany's Auto Motor und Sport.

"And we will not allow tyres that change the sporting hierarchy -- that would be simply unfair," he insisted.

"If there is suddenly a team winning that previously had problems with the tyres, then the people at home would feel fooled and turn off the TV."

Lopez also said Lotus does not accept the changes on the grounds of safety.

"A tyre that loses its tread is safer than a tyre that bursts," he insisted.

"I don't see it (the safety aspect) as such a big deal -- it's still all about money and politics. But the spectators are not fools.

"If we are making decisions not on the race track but in offices and committees, then one day there will be no spectators left," added Lopez.

He also said Pirelli should stand tall rather than be defensive.

"Actually, they should stand up and say 'We built a good tyre, a tyre that was requested, so the teams will just have to adjust and build reasonable cars'," said Lopez.