Hamilton and Bottas have swapped chassis between the Azerbaijan and French GPs in a pre-planned move Mercedes has described as being a standard rotation to even out mileage between the two cars.

Bottas has switched onto chassis #6 which had been used by Hamilton for the first six races of the season, while Hamilton has taken over chassis #4, which Bottas ran in Baku.

Having set the pace in opening practice from Hamilton, Bottas ended up just 0.008s adrift of Red Bull’s Max Verstappen in the afternoon session as the Finn looks to return to form in France following a difficult start to the season.

Hamilton appeared to be struggling to match Bottas all day on Friday and suggested he felt something was fundamentally wrong with his car in a radio message that was broadcast during FP2.

But the seven-time world champion indicated the issue was not related to the chassis change, insisting it felt no different to his previous car he drove in Baku.

“It’s a different track,” Hamilton said. "Very rarely do you have any differences between the chassis.”

In the event that either Hamilton or Bottas were unhappy with their chassis, Mercedes has a spare carry-over chassis on-site at Paul Ricard. In total, Mercedes has a batch of six identical chassis it has carried over from 2020.

“We swap parts around all the time and this is part of the planning of these carryover chassis,” Wolff told Sky Sports F1.

“They run for a second season so we are not accumulating millions of miles on one and basically that’s part of the plan.

“But it’s good to get the feedback and if it calms the driver’s mind we have a spare chassis, which is a brand new one, we can always do that.”

Hamilton is eyeing improvements in time for qualifying after a tricky day on Friday.

“I am looking at every option,” he explained. “We’ve made lots of changes, we will probably do a lot of analysis again tonight with the hope that it’s going to be better tomorrow.

“But who knows, we won’t know until we get back out tomorrow. As I said, the times don’t look terrible, we were close up at the front so at least we were in the battle.

“It’s quite a struggle this weekend I think probably for everyone,” he added. “I don’t know if it’s the track surface or it’s the temperature or these inflated tyres, they’ve put the pressures up higher than ever before - one of the highest.

“It’s difficult to say. We are all sliding around and it’s a struggle out there for everyone.”