May 29 (GMM) Tweaked Pirelli tyres will not debut next time out in Montreal, it emerged on Wednesday.

Previously, it was believed Bernie Ecclestone had pushed through the planned changes for the Canadian Grand Prix, despite the opposition of some teams.

"I did it like the old days," the F1 chief executive was quoted by Germany's Auto Motor und Sport. "I told the teams that they should be united.

"Pirelli will modify its tyres as planned," Ecclestone added.

But the 82-year-old was speaking prior to the explosion of the Mercedes 'secret' tyre test scandal, where the German squad apparently tried the proposed changes at Barcelona just after the Spanish Grand Prix.

Red Bull and Ferrari lodged a formal protest, many other teams are furious, and the FIA is not ruling out penalties.

Pirelli is defensive. "Most of the tyres that were tested (by Mercedes) were not relevant for this season," a spokesperson is quoted by German website motorsport-total.com.

"Mercedes had no advantage in Monaco."

Nevertheless, Pirelli spokesperson is also telling publications on Wednesday that the tweaked tyres - reportedly featuring a kevlar belt rather than a steel one to minimise rear delaminations - will now not debut in Canada.

Instead, two "experimental" compounds will be tested by teams on Friday, which will then "hopefully" make their qualifying and race debut at Silverstone.

"We are taking this step for the sake of sporting equality," said the spokesperson.