MOTOR SPORT:THE CIVIL WAR between Red Bull Racing drivers Mark Webber and Sebastian Vettel may still be rumbling, with neither yet willing to absolve the other for the Turkish Grand Prix clash that robbed their team of a one-two victory, but a war on a more pressing front is likely to open up this afternoon as the pair attempt to hold back the advancing challenge of McLaren in qualifying for tomorrow's Canadian Grand Prix.

The Red Bull pairing have been at loggerheads for a fortnight since Vettel’s ambitious attempt at wrestling the lead from Webber in Turkey resulted in a race-ending clash for Vettel and a scrappily salvaged third place for Webber.

And the preparations for F1’s return to Montreal after the race failed to feature last year have all been about failed attempts to put the incident to rest.

“The result wasn’t great, one car didn’t finish, and in the future there is a big chance we will race each other again,” Webber said on Thursday. “But we need to have judgment, as all Formula One drivers need to have, whether I’m lapping [HRT’s Karun] Chandhok or fighting with Seb for the lead. We should be doing what we can to make the right calls from the cockpit, as I have done for most of my career.”

Vettel meanwhile insisted the matter had been dealt with internally but still refused to accept any blame for the incident, telling reporters that “looking back, I wouldn’t change anything”.

“For me it is more important what is being discussed internally, and there everything is cleared up,” he said of meetings between the team-mates that took place at the team’s Milton Keynes HQ last week.

“So there are no open questions left. What is being written in the press is something that I cannot influence anyway, and most of the time it’s just a snapshot of what really has happened.”

Behind the ongoing row, though, lies the more significant problem of the damage done to the team’s championship chances. The Turkey crash allowed the McLaren duo of Lewis Hamilton and Jenson Button to mop up a one-two win and as the quartet head into qualifying in Montreal this afternoon momentum and, here at least, technical superiority could force the Red Bull drivers out of the category marked “pacesetters” for the first time this season.

The Circuit Gilles Villeneuve’s blend of long high-speed straights into heavy braking corners emphasises power and reliability over balance and finesse and with Red Bull team principal Christian Horner admitting his team’s Renault engine is some 20 brake horsepower down on that of McLaren’s Mercedes powerplant, Hamilton and Button have an advantage here.

Add to the mix the infamous F-duct, the driver-activated system which stalls the rear wing into a position that decreases downforce and thus elevates straight-line speed, and McLaren, which possesses the system while Red Bull is still evaluating its response, have additional ammunition to bring to the fight.

“I don’t expect the track to suit the RB6 as much as, say, Barcelona or even Monaco because the high top speeds of those using an F-duct will leave us a bit vulnerable in the race,” Webber admitted. “I know I’m going to have to work for it and reliability could be a factor for everyone on the grid because the track is notoriously tough on the cars.”

Red Bull have already suffered numerous technical problems this season, with Vettel suffering two brake-related problems in Australia and Spain, which robbed him of valuable points and also a spark plug defect causing engine problems in Bahrain. With engines at full throttle for large sections of the Montreal circuit and brakes overheated by hard-braking corners at the end of those straights, Red Bull could also be giving something away in terms of reliability to their closest rivals.

“This is a circuit where perhaps there is less opportunity for the advantage of Red Bull,” said Hamilton. “On turns four, seven and nine, the Red Bull will be quite strong on those exits but otherwise we should be strong on the straights.

“Other teams are constantly developing their cars, and we are doing the same. Hopefully our car will suit the track a bit more than Monaco and we will have a good weekend.”

It was borne out by the first free practice session with Button quickest and Hamilton third behind Michael Schumacher. Vettel was the quickest of the Red Bulls, finishing fifth, with Webber down in 14th.

Neither Red Bull driver has, however, shown his true pace this season until qualifying and with all seven poles so far won by Webber or Vettel, it will still be a tall order for McLaren, or any other team, to usurp the Anglo-Austrian team from the front of the grid. Today, though, could be the day.