Jenson Button has once more bemoaned McLaren's lack of pace - and says the team are "clutching at straws" as they look to find a solution ahead of the British Grand Prix later this month.
Button endured a miserable time at the Canadian Grand Prix this weekend, qualifying in 14th before moving up just two places over 70 laps to finish outside the points at the Circuit Gilles Villeneuve.
Team-mate Sergio Perez could only muster an 11th place finish - meaning McLaren failed to score points for the first time in 64 races.
The disappointment of having both drivers finish outside the top ten was compounded by the fact that the Woking-based team are now a massive 164 points off Constructors' Championship leaders Red Bull after just seven races.
Button says there is little hope of McLaren being able to close the gap ahead of the race at Silverstone on June 30.
"We were worse here than we have been all year compared to the frontrunners," said the 2009 World Champion. "We've got work to do."
"I'm looking forward to the next race at Silverstone, it can't be as bad as here. We're clutching at straws."
McLaren team principle Martin Whitmarsh admitted that a series of strategic errors during the race in Canada undermined both drivers' attempts to secure points even further.
"It was a tough afternoon," he said. "We got it wrong. With Button, we should have started on the 'prime' [medium] tyre. We really stayed out on the 'option' [super-soft] too long, stayed in traffic and lost a lot of time.
"In the case of Jenson, we set him lap time targets which were too slow - and he could have gone much faster. He could have pushed into the points.
"It was one weekend where we didn't get it right. We were not quick enough to be at the front but we should have been able to get in the points."
A downbeat Button admitted he was happy that the race was over, such was the performance of his car.
"The team gave me a lap time, but it wasn't quick enough," he said. "We got the calculations wrong. Once I started pushing, the pace was quite a bit better."
"I've never been so pleased to get out of a car.
"It was quite painful out there. We got lapped, easily lapped. It was like we were in a different category."
Red Bull's Sebastian Vettel claimed a dominant victory in Montreal to extend his lead in the Drivers' Championship to 36 points from Ferrari's Fernando Alsono, who came home in second.
Mercedes' Lewis Hamilton bagged the final podium spot.
The race ended on a sour note after it was confirmed that a 38-year-old marshall had been killed by a recovery vehicle while helping to retrieve Esteban Gutierrez's Sauber.
The man, who has not been named, was rushed to hospital but passed away because of his injuries.