The Brazilian was outqualified by Ericsson in both Melbourne and Bahrain - and the situation was no different in China, as Nasr lapped three tenths off in Q1 and was almost two seconds adrift in the red-flagged Q2.

"I am 100 percent convinced that the handling is not as it should be," Nasr said after qualifying.

"We started the same [set-up] and the outcome was like the last two races. I'm struggling big-time, feeling a general lack of stability of the car, especially under braking, which [Ericsson] is pretty happy [with].

"He's been happy with the car since this car was built - and I had the chance to drive the car he's driving back in the test in Barcelona and I've been pretty happy, too.

"I did what I could, I did everything I could, I feel like I drove a good lap out there [in Q1] - and still, the behaviour of the car is not like we expect it to be."

The Brazilian also confirmed that the cash-strapped Sauber team would have no spare chassis to try out until at least Russia and, when asked whether he would be up for switching cars with Ericsson for a session or two, gave an affirmative answer.

"Why not, I'm up for it. I wouldn't mind. Make the proposal to him, see what he says."

"I've shown who is strongest" - Ericsson

Ericsson, meanwhile, hinted that the pace he has produced over Nasr was not a sign of a chassis difference, but rather just an indication of the Swede's strong run of form.

"I think, at the end of last year, I was the strongest [Sauber driver] - and I've been working hard over the winter to be even stronger this year - and I feel confident in the team and with the car," he said.

"I think I've shown it very clearly this season so far who is the strongest, so I just need to keep doing my job, keep working hard and keep beating him."

Points possible for Sauber

Having qualified 15th, Ericsson believes that he will be able to challenge for points on the strength of Sauber's long-run pace.

"I'm feeling quite optimistic because, like I said, our long-run pace yesterday was quite promising, we were in the mix with the McLarens, the Force Indias, in front of the Renault and of the Haas as well," he said.

"We were in that group where we are starting - so, with that in mind, I think it's gonna be a critical race with the tyre wear, especially looking after the left front.

"I think for us that felt quite alright yesterday, so if I can manage to keep my tyres alive during the race tomorrow, I think we can be in a good chance to even be battling for points by the end of the race."

Interview by Oleg Karpov