England's cricketers are hopeful that the discovery of the new Omicron variant of Covid-19 in Australia won't impact the Ashes Tests - or their families' travel plans, Ashley Giles says.

But Giles, the managing director of England men's cricket, admitted the touring party were at the mercy of the Australian authorities ahead of talks on the issue on Sunday.

"We're obviously hoping it won't affect anything," Giles told reporters via Zoom from Brisbane. "There are going to be changes to those border controls in terms of our families being able to travel and we clearly hope that's not going to affect us. But we are in the hands of national and local governments."

England's players had expressed concerns before leaving for Australia over beginning the tour with 14 days' quarantine in Queensland and the effects on them and their families. Different states have now introduced new travel restrictions in response to the latest variant and Western Australia Cricket Association chief executive Christina Matthews has described the chances of the fifth Test going ahead in Perth as "50-50" given the state's stringent rules on travel.

"We always knew things could change," Giles said. "I guess we hoped things would change positively as we went through the series but as we've been aware over the last two years with variants, things can also change negatively.

"Can we prepare for everything? It's not really possible actually because of the big moving parts even around quarantine times and rules around different states. We will do everything we can to make sure the families are accommodated and of course that the players are happy."

The England squad plan to play a four-day warm-up match against England Lions on Tuesday, with the Test players who were involved in the T20 World Cup due to travel to Brisbane from their quarantine base on the Gold Coast on the morning of the match, along with head coach Chris Silverwood.

Rain ruined England's first, three-day, warm-up against the Lions, with further thunderstorms forecast for Brisbane this week.

"It's not perfect preparation and it's been extremely strange having some of our group so close but yet so far away," Giles said. "They've been in bubbles now for a long period with the World Cup and then coming here for 14 days. They've been very well looked after here but it is still a bubble and it's still quarantine down there for them.

"I'm certainly looking forward to getting the head coach here. Chris particularly must feel a real strange detachment being so close but so far away from a squad that's preparing for an Ashes. [It's] not ideal but the Australians are in the same boat and we've just got to try and do it better than them."

Giles said England were yet to make a call on whether Ben Stokes would play in the first Test, starting on December 8, after nearly five months out of the game to prioritise his mental health, during which time he was also nursing a serious finger injury.

"Ben seems to be going well and it's just great having him around," Giles said. "We've still got to be steady with him, he hasn't played a lot of cricket lately and, going back to that prep period, it's not ideal for anyone, but particularly the guys who haven't had a lot of cricket under their belt. We'll just keep building him up and see where we are at the end of this four-day game.

"I'm hopeful and I would always like to be confident. We've just got to treat Ben carefully, as we would with anyone else who has been in that position of not having a lot of cricket under their belts. He will be a difficult man to hold back if he is ready to go."