Newey said the success of the chassis upgrade could be critical in lead driver Fernando Alonso’s decision on his future.

The two-time champion is 45 in July and out of contract at the end of the season. He has said he is committed to a future with Aston Martin but has not decided whether to leave F1 and race elsewhere.

Newey said the update was “very important” to Alonso.

“Fernando is really looking forward to the upgrade and if it performs we hope he’ll be in the cockpit for another season,” Newey said.

“Given his experience, his feel for the car, his ability to guide development, he’s a tremendous asset. But he wants to see clear, tangible progress. If we can show that we’re moving decisively in the right direction, he’s absolutely committed to being behind the wheel.”

But Newey refused to give an estimate for the performance step he expected from the upgrade.

So far this season, Aston Martin are an average of 3.4 seconds off the pace, and even a two-second improvement would only move them up to the midfield, and would still leave them behind Alpine and Racing Bulls, the fastest two cars outside the big four teams.

“We’re predicting a large step,” Newey said, “but I’m reluctant to put specific numbers out there because our simulation tools aren’t yet as sophisticated or well correlated as they need to be.

“Historically, at this team, there hasn’t been enough investment in engineering simulation tools – not just project management systems, but the core physics tools themselves.

“We’re putting that investment in now, but you don’t rewrite and validate those tools overnight. Correlating them properly with the real car takes time.

“At the moment, they’re improving, but the real gains from that work will come later in the year.”

This is an indirect reference to the fact that over the past few seasons Aston Martin have introduced developments expecting improvements but these have not materialised on track.

This will be the first time a major upgrade has been tested with Aston Martin’s new tools and procedures and with Newey at the helm.

A development to the Honda engine, which is the least powerful on the grid and is said by insiders to be lacking 50kW (67bhp) compared with the best, is also expected this summer.

But the company has not said at which race it will be introduced.