Twenty-five players have been named by the National Selection Panel for the blockbuster all-Australian showdown in Southampton next week that will decide Australia's Ashes squad.

The extended playing group is comprised of the 15 players already in England with the Australia A squad, seven players from Australia's World Cup group and three players - Peter Siddle, Cameron Bancroft and Marnus Labuschagne - who have been in the UK participating in County cricket.

Squad: Cameron Bancroft, Jackson Bird, Joe Burns, Alex Carey, Pat Cummins, Peter Handscomb, Marcus Harris, Josh Hazlewood, Jon Holland, Travis Head, Usman Khawaja, Marnus Labuschagne, Nathan Lyon, Mitchell Marsh, Michael Neser, Tim Paine, Kurtis Patterson, James Pattinson, Will Pucovski, Peter Siddle, Steve Smith, Mitchell Starc, Chris Tremain, Matthew Wade, David Warner

The match from July 23-26 will pit Australia against Australia A in a 12-on-12 contest which, despite not holding first-class status, is expected to be extremely intense given Ashes spots will be on the line.

Australia's final Ashes squad will named after the game in Southampton ahead of the first Test at Edgbaston, starting on August 1.

It will be the first time since last year's Cape Town incident that Bancroft, Steve Smith and David Warner will be in the same squad having served lengthy bans for their involvement in the ball-tampering plot.

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While Smith and Warner have been front and centre as part of Australia's World Cup campaign, Bancroft has been in sparkling form as captain of Durham, scoring 1075 runs at 57 in first-class and one-day cricket.

"Cameron was making a fair amount of headway when he played Test cricket last for Australia and that was in South Africa," said national selector Trevor Hohns.

"What he's done is he's got on with business since he's been able to play again. He's playing with Durham in the County Championship, so he's doing everything he possibly can to get himself back into consideration and back into the Australian squad.

"He's scoring runs on a pretty regular basis so he has been included in that 25-man squad along with two others playing county cricket."

Alex Carey is one of three wicketkeepers in the group, alongside Test captain Tim Paine and Tasmania's Matt Wade, and enters on the back of a breakout World Cup with the gloves.

Batting mainly at No.7 before his promotion to No.5 in the semi-final loss to England, Carey scored 375 runs at 62.50 and led the tournament in dismissals with 20 (18 caught, two stumped).

"He's proving himself to be a very smart cricketer," said Hohns. "He played very well in the World Cup.

"Batting-wise he was very, very good. He showed calmness in a lot of diff situations. He's been very impressive.

"We've been very impressed with his glovework for some time now so he's progressing nicely."

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Usman Khawaja's participation in the highly-anticipated contest is uncertain after he suffered a hamstring strain in Australia's World Cup loss to South Africa in Manchester last Saturday.

There was no room in the squad for allrounders Glenn Maxwell and Marcus Stoinis.

Men's head coach Justin Langer said both Maxwell and Stoinis would be "really disappointed" with their individual World Cup performances; Maxwell averaged 22.12 in 10 innings while Stoinis averaged 14.5 with the bat and 34.85 with the ball having battled injury for most of the tournament.

"Let's put it this way: We consider the 25 that did get chosen for this game as more in contention than those guys," Hohns explained. "It's unfortunate but that's just where we're at right here and now."

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Just how the two teams will be chosen for the selection showdown is yet to be decided, but Paine has thrown his support behind a draft-style system.

Hohns says his panel has the core of the Ashes squad already pencilled in and is looking forward to watching the Test aspirants make one final push for selection.

"We are expecting a full-on contest between players who will be hungry to succeed," Hohns said.

"In one way it is a shame that some players will have to miss out as every player in Southampton will have a strong case for inclusion in the Ashes squad, but the positive is that this group shows we now have a degree of depth, which stands us in good stead both now and in the middle term.

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"The Australia A tour and the intra-squad match were set up some time ago with the specific purposes of getting the players game time in English conditions against the Dukes ball to give them the best chance of success in the upcoming Ashes series.

"We have not won a Test series in the UK since 2001 and our aim is to leave no stone unturned in an attempt to buck that trend. The ongoing A tour and the match in Southampton are part of that process."

Squad: Cameron Bancroft, Jackson Bird, Joe Burns, Alex Carey, Pat Cummins, Peter Handscomb, Marcus Harris, Josh Hazlewood, Jon Holland, Travis Head, Usman Khawaja, Marnus Labuschagne, Nathan Lyon, Mitchell Marsh, Michael Neser, Tim Paine, Kurtis Patterson, James Pattinson, Will Pucovski, Peter Siddle, Steve Smith, Mitchell Starc, Chris Tremain, Matthew Wade, David Warner

2019 Qantas Ashes Tour of England

Tour match: Australia v Australia A, July 23-26

First Test: August 1-5, Edgbaston

Tour match: Australians v Worcestershire, August 7-9

Second Test: August 14-18,Lord's

Third Test: August 22-26, Headingley

Tour match: Australians v Derbyshire, August 29-31

Fourth Test: September 4-8, Old Trafford

Fifth Test: September 12-16, The Oval