Robert Kubica has admitted that tensions are showing behind the scenes at Williams.

The British team is having an awful 2018 season, having lost key engineers Ed Wood and Dirk de Beer and also set to lose main sponsor Martini.

"The impact on the team? We're obviously having quite a difficult start to our year," Claire Williams said in Montreal.

Reserve driver Kubica agrees, telling Sky Italia: "Let's say it like the politicians. Our season is a bit uphill.

"It's not easy to solve it. In the race in Monaco there were good signs, but then there were problems with overheating. We cannot even manage to solve the small problems at the moment."

When asked about the atmosphere behind the scenes, the Pole answered: "There is a rule in F1 that if things are all good, they're good from the engineers to the caterers.

"But if you go two seconds down ..."

Claire Williams continued: "We have a really strong technical team back at Grove who are working really hard and really cohesively, and that's the most important thing.

"Everyone just has their head down and is trying to get us out of the trouble we're in at the moment."

Williams are rock-bottom of the constructor rankings with four points ahead of tomorrow's Canadian Grand Prix.