Pirelli motorsport director Paul Hembery was a notable absentee from Friday's official press conference in Montreal, but later revealed that he had been happy with the performance of his employer's latest tyre tweak.

Pirelli took the unusual step of withdrawing Hembery from the FIA press call on legal grounds in the wake of the ongoing row over a three-day tyre test that took place between the Spanish and Monaco grands prix. The Briton had been scheduled to appear alongside team principals Ross Brawn, Stefano Domenicali, Christian Horner, Martin Whitmarsh and Monisha Kaltenborn.

"We're going to a tribunal," Hembery later explained to reporters in the Montreal paddock, "If ever you're going to a tribunal any lawyer will tell you that, at that point, you have a formal process to follow."

Despite not presenting the opportunity to be quizzed about the latest development tyre, which was due to make its race debut in Canada, but was later restricted to free practice use instead, Pirelli's post-session communications confirmed that the feedback had been positive.

Although the first 90-minute session only allowed limited running on the unmarked rubber due to rain, the afternoon session saw all eleven teams complete laps on the tyre, which features a Kevlar belt in place of the steel one thought to be a cause of a spate of delaminations in previous events.
"The rain in the morning meant that the drivers didn't really get to assess the new construction of the rear as thoroughly as they would have liked to, but initial feedback has been positive," Hembery confirmed.

"We'll be analysing a lot more data about this new construction over the next few days before drawing a final conclusion, but we don't expect this to be a massive change. It's only a minor alteration to ensure that none of the previous delaminations - which do not impact on safety - recur, and it doesn't affect the fundamental characteristics, performance or durability of the tyre."

With only two sets of the development rubber per team and use prohibited beyond Friday's two sessions, the rest of the weekend will be contested on the nominated medium and supersoft compounds, and Hembery was happy with they too had performed.

"Canada is always one of the most challenging circuits for the tyres, because of the layout of the track and also the heavy braking, which puts plenty of heat into them," he reflected, "Conditions today could well be representative of what we have in the race, with around 17 degrees ambient and track temperature, and we've seen good durability and performance from both compounds so far - with little graining despite the cool temperatures."

After taking flak for the four stops Fernando Alonso used to win the Spanish Grand Prix, Hembery refused to be drawn on what Canada could bring, particularly with the rain not helping to produce a true picture of the conditions expected on race day.

"It's hard to make a prediction about the number of pit-stops at this point because the track is still very green and there are so many variables here," he concluded, "But we've seen some long runs from the supersoft in practice with no significant drop-off in performance, so this certainly looks set to be the tyre to qualify on tomorrow."