Everton are set to submit a formal complaint to the FA following Chelsea boss Jose Mourinho's attack on England striker Andrew Johnson.
The move will take the growing row to a new level and will force the FA into considering Mourinho's remarks following Chelsea's 3-2 win on Sunday at Goodison Park.
Everton have taken legal advice and are threatening action on Johnson's behalf against Mourinho for alleged defamation of character.
Everton claim that Mourinho accused Johnson of diving and insist that damages the player's reputation as well as the club's.
Initially Everton issued a statement on their website demanding that Mourinho retracts his remarks, but the FA said they would not act unless the complaint was made formally.
Everton had also hoped that there would have been some conciliatory contact from the Premier League champions, but this has so far not been forthcoming.
Everton spokesman Ian Ross said: 'We will now make a formal complaint to the FA over Jose Mourinho's remarks regarding Andrew Johnson.'
Everton have also been puzzled by advice from the FA yesterday that they were unlikely to take disciplinary action against the Chelsea boss.
But the Merseysiders are aware that there are several interviews with Mourinho following the match with differing comments.
But the one statement they are basing their complaint on is from a Sky Sports interview in which Mourinho says: 'I know he dives.'
Everton have a full transcript of that interview and it will form the basis of their complaint.
An FA source explained today that their compliance department were already considering Mourinho's remarks before Everton's website statement, but that they were unaware of the Sky Sports interview.
A spokesman said: 'If we receive a formal complaint, of course we will treat it seriously.'
Mourinho was also reported to have said: 'He's dangerous for opponents because you can't trust him.'
Chelsea have yet to comment officially, although they have privately queried why Everton did not complain when Arsenal boss Arsene Wenger questioned Johnson's style earlier in the season.
What is clear now is that this situation will result in a major row between two Premiership clubs.
The specific incident Mourinho was complaining about occurred when Johnson hurdled goalkeeper Hilario in the first-half at Goodison, yet TV replays suggest that Johnson had been pushed in the back by Khalid Boulahrouz before he fell.