England captain Alastair Cook admits that his 100<sup>th Test is sure to be the toughest of his career as England look to pull out all the stops in the hope of turning around their Ashes fortunes.

England travel to Perth ahead of Friday's third Test having failed to overcome the Australians thus far, losing in Brisbane by 381 runs and Adelaide by 218 in respective Tests.

"Your next challenge is always the toughest," told BBC Sport.

"Our confidence has taken a hit after the first two matches but the squad has made a real conscious effort. We have to look forward, rather than look back.

"I don't think it's been about lifting the players. That hunger and desire has always been there in this side. We have got another opportunity to show it this week."

A loss in Perth will see England hand the famous Urn back to the Australians while a win could be the start of an unlikely comeback. Such a feat would see the visitors take their place in history as only the second team to have fought back from 2-0 down. The last England side to do so was led by Don Bradman in 1936-37.

Meanwhile Australian Captain Michael Clarke will also play his 100<sup>th Test in Perth and will wait until after the toss before naming his side, confident that his fast bowler Ryan Harris will fight off a knee niggle to face England.

As summer temperatures in Perth soar, both captains look ahead once again to their 100<sup>th Tests: "In regards to being your 100th Test, it's not a focus at all. It's fantastic that I've been able to play 99 Tests for my country and it's something that I'm proud of," said Clarke.

"But it's about having the chance to win the Ashes and continue to perform like we have in first two Tests."

Said captain Cook: "It's a huge honour for me to join the 100 club, one I never thought I'd get when I started playing.

"It is a special day, and it would make it even more special if we can produce a performance we are capable off."