Cook says team unity no easy task during Ashes

England captain Alastair Cook said team spirit could never be taken for granted as Australia battled to present a united front after accusations of dressing room disharmony made by ex-coach Mickey Arthur.

The South African was sacked just 16 days before the first Test against Ashes-holders England at Trent Bridge this month and replaced as Australia coach by former Test batsman Darren Lehmann.

Reports said Arthur, fired two years before his contract was due to expire, was seeking up to Aus$4 million (US$3.69 million) in compensation, claiming he was discriminated against because he was South African and "didn't understand the Australian way".

According to Australian broadcaster Channel Seven, legal documents reveal a major feud in the team between captain Michael Clarke and former vice-captain Shane Watson.

Clarke allegedly described the role of Watson and his faction as a "cancer" with Arthur calling himself the "meat in the sandwich" between the conflicting camps.

England had problems of their own last year when Kevin Pietersen, after scoring a superb Test hundred against his native South Africa at Headingley, was briefly dropped from the side for allegedly sending text messages critical of then England captain Andrew Strauss, who has since retired, to Proteas players.

"I can only speak what happen in our dressing room and clearly last summer we had a bad experience," said Cook.

"It shows how hard you've got to work at your team because a fully united team does help your cricket and we constantly have to work at it."

Meanwhile, Clarke insisted his side were pulling in the same direction ahead of Thursday's second Test at Lord's, where Australia will look to level the series after a dramatic 14-run loss at Trent Bridge last week.

"The team is as galvanised as I can remember any Australian team," Clarke said. "All the boys are in a really good place and we're looking forward to Thursday.

Clarke also praised the role of Lehmann in creating dressing room harmony, saying: "We've got a fantastic group, with a great coach. He's united us. We're heading in the right direction."

Arthur said he was disappointed that what he thought were confidential legal documents had been leaked to the media.

"I have kept them confidential. Unfortunately, others have now made them public," said Arthur. "I want to stress how important to me the members of the team were, and still remain to me. The welfare of the Australian cricket team is upmost to me."