Chelsea claim unhappy French defender William Gallas sensationally threatened to score an own goal and refused to play for the club before he was sold to Arsenal as part of the deal which took Ashley Cole to Stamford Bridge.

The Premiership champions took the unprecedented step of issuing a statement to inform their fans about the lack of respect the defender showed the club in a bid to get a move away from Chelsea.

The statement revealed how he initially refused to play against Liverpool in last season's FA Cup semi-final and how, if selected to play against Manchester City in the first game of this season, he threatened to score an own goal, get sent off or make deliberate mistakes.

The club statement read: "Chelsea believes it is important for our supporters to be made aware of the full facts regarding William Gallas and the lack of respect he showed to the fans, the manager and the club.

"Despite leaving he continues to attack Jose Mourinho and this cannot be left unchallenged. Chelsea made William Gallas a very substantial and attractive new contract offer to stay towards the end of last season. This was rejected.

"The issue was purely one of money, despite his public comments that he wanted a new challenge, to play abroad and so forth. These were just a smokescreen to cover up the fact he was hawking himself to the highest bidder. Having failed to secure his demands, his position became increasingly intransigent and unacceptable.

"He initially refused to play against Liverpool in the FA Cup semi-final last season in an effort to force an increased contract offer. As is now well-documented he refused to join up with the team in Los Angeles during pre-season, despite agreeing the dates for his return as the other World Cup players did, with the club.

"When Jose Mourinho generously offered him a way back into the "family" after the American tour, this was thrown back in the Chelsea manager's face. The manager told him that, even if he did not agree a new contract but returned to the "family" and abided by the rules, he would still select the best players available and would not punish him playing-wise.

"However despite meetings to try to resolve the problems Gallas made it clear to Jose Mourinho he would never play for Chelsea again. Before the first game of the season against Manchester City, when only four defenders were available and John Terry was doubtful with an injury, he refused to play.

"He went on to threaten that if he was forced to play, or if he was disciplined and financially punished for his breach of the rules, that he could score an own goal or get himself sent off, or make deliberate mistakes.

"Clearly this was a totally unacceptable situation for the manager, the team and the club. So a collectively-agreed solution in Chelsea's interests had to be found, hence his departure.

"Chelsea has a wage structure in place that is valued not only on the contribution of the player to the manager and the team, but also on a player's respect for the club and contribution to the promotion and image of the club off the field. Every player is expected to play their part in this.

"William Gallas rarely recognised these responsibilities. He also failed to recognise the role Jose Mourinho and Chelsea played in helping him become a double Premiership champion for a player whose only league title prior to that had been in the French Second Division."

Much of Chelsea's statement will explain why Mourinho called on the player to make public the reasons why he was not being considered for selection by the club.

Mourinho asked the player to hold a press conference before he was sold to Arsenal on deadline day.

Meanwhile, Chelsea also hit back at France coach Raymond Domenech and defender Lilian Thuram after they spoke out against Mourinho over the selection of Claude Makelele.

Mourinho had accused Domenech of treating Makelele like a "slave" for not allowing the player to quit international football. But Domenech clearly did not understand Mourinho's use of the word as a metaphor to highlight Makelele's situation.

The France coach claimed Mourinho's use of the word was both "staggering and insulting" while Thuram insisted the Chelsea coach said it to be purposefully offensive.

However Chelsea hit back saying in a further statement: "Ill-considered comments regarding Claude Makelele's international career continue to come from the French camp, in particular Lilian Thuram, and the French national team coach, Raymond Domenech.

"Jose Mourinho was correct in giving strong backing for our player, and he was fully supported by Chelsea FC on this. Thuram and Domenech appear not to appreciate a manager's support for his player. They also fail to understand Jose Mourinho's comments regarding 'slavery' which were purely a metaphor to illustrate the Makelele problem, a figure of speech rather than a literal comparison with slavery as a social and political issue.

"As a result of their failings, deliberately inflammatory comments will only cloud a problem which is on its way to being resolved. Claude, Chelsea Football Club and the French Football Federation hope to have a resolution after the current round of international matches."