The row between Manchester City and Newcastle United over Joey Barton's protracted transfer to the north-east has intensified after City hit back at Magpies boss Sam Allardyce.
City are annoyed that the former Bolton Wanderers manager has suggested that details of Barton's contract had been leaked by the club.
The controversial midfielder has a clause in his contract which entitles him to £300,000 from City if he leaves the club without asking for a move.
City have refused to pay the amount, and the Professional Footballers' Association are now involved as mediators in the row.
Allardyce said on Tuesday: "They (City) are out of order. This is a private matter, a confidential issue that should not have been made public.
"I'm flabbergasted and want the situation resolved. I'm just trying, as Newcastle manager, to secure a player of this kind and quality and the deal has been held up.
"I can't understand it because City didn't pay anything for this player as he came through the youth system, and they are selling him for over £5million.
"But it is not really for me to comment. All I know is that this is a matter for Joey to sort out and I hope it is resolved as it has stopped him putting pen to paper."
City spokesman Paul Tyrrell has responded to Allardyce's claim, saying: "At no time have we divulged the details of Joey's contract, or would we ever do so with any player.
"Sadly this is now in the public domain through no fault of Manchester City.
"It's disappointing that Sam Allardyce has chosen to make these claims public. We will continue to have a good relationship with Newcastle."