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Ponting scored only 12 as his side struggled once more on Thursday
Former Australia captain Steve Waugh believes current skipper Ricky Ponting will quit international cricket if he loses the captaincy.
Ponting, who made 12 on Thursday as Australia scored 268 all out in Perth, is under increasing pressure following his side's poor start to the Ashes.
Waugh told the BBC's Test Match Special it would be "very hard" for Ponting to continue if he was no longer captain.
"I don't know what would motivate him in that situation," added Waugh.
Australia suffered a run of seven straight defeats in all forms of the game in the build-up to the start of the Ashes and headed into the third Test in Perth 1-0 down in the five-match Test series.
They were outplayed again by England on the first day at the Waca on Thursday and Ponting faces becoming the first Australia captain in 120 years to lose three Ashes series.
Speaking ahead of the third Test, the 35-year-old suggested he would not quit, adding the decision over who should lead the side was "completely out of my hands".
Ponting, who is the most successful captain of all time with 47 Test wins, continued: "The powers that be will make those decisions I guess at the end of the series, or after this Test match."
It is rare for former Australia captains to continue in the side and
Waugh believes that should Ponting lose the role, it would mark the end of his successor's international career.
"He's played 150 Tests and has an amazing record, he's batted number three most of his career, I can't see why he'd want to slip down the order and not be captain," said Waugh.
"He's had a great career and I'd be very surprised if he took that option, if that was the option available to him."
Waugh added that although Ponting should listen to advice about his future, only the Tasmanian could make the right decision.
"Ricky will know what's going on inside of him. You've got to be brutally honest with yourself - is this the right time, have I got more left, can I improve, can I take the side up to the next notch or is it going the other way?" said Waugh.
If people count against such a champion they generally come back and show the critics to be wrong
"He's got to look at himself in the mirror and he's the only one that can answer that question."
Ponting averages over 54 in Tests but his poor run of scores with the bat - he has only passed fifty once so far this series - is adding to the pressure, but Australia batsman Mike Hussey has backed him to regain his form.
Hussey was himself on the verge of being dropped before the series but has passed fifty in four successive innings and believes his skipper can rebound in similar fashion.
"If people count against such a champion, they generally come back and show the critics to be wrong," said Hussey.
"I have no doubt it will be the same on this occasion.
"Ricky is such a champion batsman, champion bloke and champion captain that I am sure he will be fine."
However, BBC cricket correspondent Jonathan Agnew confirmed "the pressure is mounting on Ponting".
"He cannot keep failing to score runs and seeing his team lose. His time in charge may well be coming to an end," added Agnew.
"Who knows what might happen if things continue this way into Sydney [venue of the fifth and final Test].
"If the situation determines that the Ashes are gone and he can't score a run, he might well feel that he has had enough by then."
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