The world championship leader complained over the radio that Hamilton was compromising his running by backing off to find clear track around the circuit Gilles Villeneuve, when he was trying to complete a long run for race preparation.

While Vettel said he understood that Hamilton wasn't deliberately baulking him, it did disrupt his session.

"It was a bit annoying because I was a bit stuck," said Vettel after FP2. "I wanted to get some consecutive laps to get a good feel for the car.

"[Hamilton] made a gap [to the cars in front], then he did a mistake, then he made a gap, then he did a mistake, so it's unfortunate.

"It was breaking a bit of the rhythm but towards the end, I understood what we need. The problem was when you try to do consecutive laps, with traffic, it's not ideal.

"I'm sure he wasn't doing it on purpose, he was trying to do the same, get a feeling for the car. But it was slippery today and easy to do mistakes – I spun twice."

Hamilton was surprised to learn that Vettel had complained on the radio, saying: "What's there to complain about, it's bloody practice, man!

"This is a difficult track in terms of traffic. I had someone in front of me so I had to back up and that meant he had to back up. That's just the way it goes, nothing to get emotional about."

Hamilton did suggest, however, that something needs to be done about drivers backing off on the long straight before the final chicane, as it can lead to dangerous closing speeds between cars.

He asked during the session to be put through on the radio to F1 race director Charlie Whiting, and said he wants to see a system put in place for safety reasons.

"Coming down that back straight at over 200mph there are people backing up and waiting to start their lap with a gap," he said.

"They're like a dot in the distance and then that dot…before you know it there's a difference of at least 100-200km/h in front of me and they're going at a snail's pace and it's dangerous.

"One day somebody is going to get caught out, so I was saying maybe we should be sensible and we should find a gap at Turn 10 and then you have to be on the gas and you can't slow down.

"It would be safer for everyone. We've got a drivers' briefing where we can tell him."

Additional reporting by Lawrence Barretto