Pirelli's new tyres will not race in the British Grand Prix

Formula 1's tyre supplier has been looking for a solution to the delaminations that a number of drivers have suffered in the early stages of the season, and last weekend teams tried out a new specification that replaced the current steel internal belt with a Kevlar version.

If the teams had all been happy with the new rubber, then the idea was for the new specification to be raced from the British GP.

But with wet weather limiting running in Montreal, and the teams that are happy with the current tyres reluctant for there to be a change at all, Pirelli has decided that the new tyres will not be raced at Silverstone.

Instead, Pirelli will introduce revised bonding procedures to the current tyres to help ensure the tread stays attached, but may elect to trial the Kevlar-belt tyres in practice again so teams can have another look.

Pirelli motorsport director Paul Hembery told AUTOSPORT: "We are not going to race with the new tyre as we did not get much of a chance to test it here [in Canada].

"We have some internal specification changes - process changes - that we think will go the full way to curing the delamination issue that we have seen.

"That is good from many points of view, as it means teams will be working with the same tyre they started the year with.

"But it is probably not good for some teams that are struggling with the front tyre."

Pirelli has always insisted that although the delaminations are not good for its image, its products have never been unsafe because the tyres have remained fully inflated in each incident.

However, world championship leader Sebastian Vettel made it clear after his victory in Canada that his only unhappiness at the tyres this season has been on safety grounds.

"The criticism we had or I expressed was not based on performance. I think it was based on safety," he said.