Rosberg at fault as Webber fails.

Mark Webber was left frustrated with team-mate Nico Rosberg after the Williams driver failed to perform in qualifying for the second straight race in Montreal.

After qualifying down in 17th place at Silverstone, the Australian was keen to produce some kind of form ahead of the Canadian Grand Prix, but instead failed to make it into the second part of qualifying after being baulked on his fast lap by non other than his own team-mate - who had himself just made it through to the second phase.

"The car was quick enough to get through to the next group of course and I was doing everything I could to achieve this," Webber said, "but it was very frustrating to get caught behind my team-mate on the back straight which hurt me into the last corner. It was a shame to lose so much time, but that's the way it goes and I am not here to give a shopping list of excuses."

While rookie Rosberg was quick to apologise to his team-mate for the error - telling ITV1 that he was sorry to have unintentionally slowed the his team-mate - the fact the German went on to qualify in sixth place meant it was even more disappointing for the team to see Webber out of the equation so early.

"It was obviously unfortunate for Mark not to make it beyond the first session," technical director Sam Michael said. "We changed our plan to go from one timed lap to two timed lap runs and that meant the cars were stacked very close together without the usual separation of 30 seconds, but we couldn't maintain the gap because of the time left in the session and Mark suffered from traffic with Nico on his timed runs.

"It was a good day for Nico who just missed out on the top four by half a tenth and we now will consider our strategy for two cars starting from different parts of the grid."