Harmison must play - Stewart

England's former captain and wicketkeeper, Alec Stewart, believes that Steve Harmison has to be picked for Thursday's crucial Test at the WACA despite concerns about his form, because he is a proven matchwinner, and winning the match is what England have to do to have any hope of retaining the Ashes.

"I'm probably his biggest fan," Stewart told reporters in Perth. "On his day, when he's bowling well, he's probably the best bowler in the world. He got to No. 1 in the world 18 months ago, and though at the minute he's short of that level, he's still a matchwinner. We've got to win this Test match, so I'd still err on picking him, because I know what he's capable of doing."

After Harmison managed just one wicket for 288 runs in the first two Tests at Brisbane and Adelaide, all manner of theories started flying around about his form and fitness, but Stewart believes that his whole problem boils down to one thing. "I believe it all starts with confidence," he said. "If he's confident in his own ability, then everything else goes hand in hand.

"People always talk the technical thing," added Stewart. "Is he coming down with the ball the wrong side of his wrist, is his head not coming down the wicket straight? So long as he's confident. That's the biggest thing. We've got to get back into this series, and confidence plays a huge part in anyone's life, in anyone's job. If you're confident, you perform that much better. If you go out there a little off the pace, then it's going to be hard work."

Stewart believed that confidence was also the key for England's beleaguered spinner, Ashley Giles, whose place is under increasing threat from the people's favourite, Monty Panesar. "I think Panesar will get a game because we need 20 wickets to win a Test match, but I wouldn't discount England playing two spinners," he said. "They are two different types of spinners, and talking to some of the Western Australian boys say that this year it has spun [at the WACA].

"Giles has been out of all cricket for 12 months," added Stewart. "I thought he bowled very well at Brisbane, but for some reason the media both here and at home are getting on his back a little bit. He always produces very good results for England. I've played with him and I've been watching him since. He's still got a role to play and again it's a confidence issue. If he gets an early wicket we'll see what Ashley Giles can do.

"You don't become bad players overnight," Stewart continued. "I'm a fan of Ashley Giles, and I'm disappointed to see some of the former England players, who'd have played in the same side, criticising him. They know how tough international cricket is. Everyone goes through bad patches, but good players come out of them, and Ashley Giles is a good cricketer."

Stewart, who top-scored with 69 in England's festival match at Lilac Hill on Friday, had some encouraging words for Panesar as well, but warned that England's fans shouldn't expect miracles if he does finally get his chance on Thursday. "That was the first time I've been on a cricket field with him and the lad can bowl," he said. "He's got good variation, change of pace, change of flight, and he's a very hard worker as well.

"He impressed me with his passion for the game, and I think he'll play," Stewart added. "But just because he does play it doesn't mean we'll become world beaters. He's not Shane Warne, but he's got the potential to be a very, very fine left-arm spinner.

It was Warne who caused England's final-day downfall at Adelaide, and Stewart was unstinting in his praise "Shane Warne is certainly the best bowler I've ever played in my era, and he's probably the best bowler the game has ever seen," he said. "When he eventually gives it away it won't just be a hole in Australian cricket, it'll be a hole in world cricket. He's pure theatre. It was a challenge to play against him and now I'm this side of the rope it's still good to watch him.

"He got the better of England at Adelaide but that's the first time for a while, to be honest," added Stewart. "Even though he got 40 wickets in England, England's method under Duncan Fletcher has been to take positive options. When we played in the 1990s it was very much about survival, which isn't the way to play Warne and I speak from experience. You have to take the attack to him, and not allow him to smother you and your scoring options."

On the thorny subject of England's wicketkeepers, Stewart believed that there was healthy competition between Geraint Jones and Chris Read, but added that the compacted England schedule made it difficult to envisage any changes behind the stumps. "Geraint has kept wicket really well," said Stewart. "His keeping is Test-match standard, and his batting, on its day, he is a Test match No.7, without a doubt.

"Read has matured as a cricketer, and his glovework is never going to be an issue, but he knows that at No. 7 spot, you have to score runs. In his two Tests against Pakistan he showed glimpses of what's he's capable of doing, but Jones has been given the nod, so it's down to Jones to mess up. With the itinerary as it is, it's difficult to stake a claim and say 'pick me'. But they are both competing."

So too are England, added Stewart, who refused to concede that the Ashes were over already. "I'm always the optimist," he said. "While there's still hope there's a way. It's going to be tough and it's only been done once in the history of cricket., but we can still come back. The players have really got to believe they can do it, though. If they are just saying they can do it but don't believe it, there's no point in going out there."