Ian Watmore, the ECB chairman, has admitted that this winter's Ashes campaign could remain in doubt right up until the moment that Joe Root and England's Test team arrive in Australia on November 6.

The ECB are in the process of reviewing the tour's Covid-safe conditions, which they received from Cricket Australia on Friday following consultation with Australia's state and federal governments.

While the conditions, as they stand, are understood to include some flexibility on quarantine arrangements, including the prospect of the players' families joining them on tour, the prospect remains of a number of high-profile withdrawals.

The matter is further complicated by the preceding T20 World Cup in the UAE. Should England's white-ball team reach the final of the tournament - as they did five years ago in India - then the multi-format contingent could arrive in Australia up to ten days after the Test specialists, creating further potential quarantine issues.

Speaking on Tuesday, even Root himself - in the form of his life and "desperate" to take part in one of the highlights of a player's career - admitted he could not yet say for certain whether he would be travelling to Australia.

"There is no simple date it must be decided by, apart from when that plane goes to Australia," Watmore told The Daily Mail. "Joe and the players not involved in the World Cup will be leaving in the first week of November so we have until then to change things.

"We are trying to build up a picture, either confident or less confident, of the conditions. There are issues to sort out with Cricket Australia, there are issues for CA to sort out with their government and for the federal government to sort out with state governments. It is a complicated picture.

Every player I have spoken to, if you dangle an Ashes in front of them it is the most important thing for them

ECB chairman Ian Watmore

"CA know what we need to make the tour successful and they're working to deliver it. We need to see the detail, check it out with the players and management and either push back or commit."

Despite the attempts to put the players' minds at ease, the Covid situation in Australia remains fluid, as demonstrated on Tuesday when Tasmania pulled out of their Sheffield Shield fixture against Queensland in Brisbane, after four new Covid cases in the state raised fears of a snap lockdown.

Likewise, the Perth Test, scheduled to begin on January 14, looks likely to be relocated unless the players and their families can be granted an exemption from the 14-day quarantine period currently required by the Western Australia government.

"It's not a red-line type of discussion, but we're working hard to provide an environment in which our players and their families want to go and perform to their best," Watmore added. "If Australia can deliver that, great, if not we may have to have more challenging discussions."

There remains the possibility of sending a weakened team to compete in the series, but Watmore echoed Root's own thoughts on the matter, insisting that an Ashes tour is a highlight of any player's career.

"Every player I have spoken to, if you dangle an Ashes in front of them it is the most important thing for them," Watmore said. "They want to prove themselves on that stage. We have to concentrate on getting conditions with Australia that enable us to get our best team forward."