Mahmood is not yet a certain starter in the England Test team

Gatting told BBC Five Live: "Mahmood bowled some wonderful spells last summer but then bowled some bad ones.

"He's the sort of bowler, six foot odd and 90 miles-per-hour, that we need as back-up, and he could be as important as Jones was in the 2005 Ashes.

"If he can work on his consistency then his confidence will grow."

Interview: Former England captain Mike Gatting

Interview: England bowler Sajid Mahmood

Lancashire paceman Mahmood, 24, has only played five Tests with a best performance of 4-22 in England's win against Pakistan at Headingley this summer.

Jones, one of the heroes in 2005, is injured and misses England's Ashes defence.

Mahmood, included in England's squad for the ICC Champions Trophy, acknowledged on Sunday consistency was an area where he needed to improve.

Gatting said the Champions Trophy, although played in the one-day format, will be a good arena for England to work on confidence levels ahead of the Ashes series, which begins on 23 November.

I think we have got a much more settled side than Australia have at the moment Mike Gatting

He said: "We need to see the fitness of people. One or two people have got to cement their places, use it as very good practice, both mentally and physically and for their skills.

Gatting, whose 1986-87 tourists were written off in the media before winning Down Under, was at Lord's to see the delicate Ashes urn begin its three-month tour of six Australian cities.

He said in terms of team selection, Australia had more questions to solve than England.

"You're not quite sure what the middle order's going to be," he said. "And you're not quite sure who's going to be the fourth or even fifth bowler.

"They don't know if it's Mitchell Johnson, [Nathan] Bracken, [Shaun] Tait, an ageing [Michael] Kasprowicz.

"Or is it going to be [Jason] Gillespie who's been in or out? Is it going to [leg-spinner Stuart] MacGill? But Shane Warne perhaps doesn't like MacGill in the same side as him.