SYDNEY, Jan 3, 2022 (AFP) - Ben Stokes insisted Monday he has no ambition to be England captain with the star all-rounder throwing his support behind under-pressure incumbent Joe Root and beleaguered coach Chris Silverwood.

Root will become his country's longest-serving Test skipper at the fourth Ashes Test in Sydney on Wednesday, surpassing predecessor Alastair Cook's 59 matches in charge.

But he is under the gun after overseeing three consecutive heavy defeats to Australia with some pundits, including Ricky Ponting and Geoff Boycott, scathing about his captaincy.

There are few obvious viable candidates to replace him with vice-captain Stokes at the top of the pile, a move championed by former captain Mike Atherton, among others.

But the 30-year-old said he was not interested.

"I've never really had an ambition to be a captain," he was quoted as saying by the BBC.

"Captaincy is more than about setting fields, picking the team, making decisions out there in the middle. A captain is someone you want to go out and play for. Joe Root is someone I always want to play for."

Stokes has led England once previously, a Test defeat by West Indies in 2020 when Root was on paternity leave.

Atherton is among those who believes 31-year-old Root's time is almost up and that Stokes could do the job.

"Root has been a good England captain, and has always carried himself superbly and is an incredible ambassador for the sport," he wrote in his column for The Times last week.

"But having done the job for five years and having had three cracks at the Ashes, including two awful campaigns in Australia, it is time for someone else to have a go.

"Ben Stokes is a viable alternative, having done an excellent job as a stand-in briefly in the summer," he added.

However, Stokes said he doesn't believe Root is ready to give up the role.

"I don't sense that at all with Joe," he said. "He's brought this team a long way. He's done some great things.

"Obviously, this series hasn't gone too well, not from a captaincy point of view, but from a team and results point of view.

"It's totally Joe's decision," he added.

Stokes also backed Silverwood, who will miss the Sydney Test after a family member contracted Covid-19. He is in isolation in Melbourne with batting coach Graham Thorpe expected to fill in.

"All the hype in the media recently about their futures, it's your job to write that, but they know full well they have the support of everyone in there and that's all that matters," Stokes said.