Sir Alex Ferguson is facing a Football Association charge and a possible touchline ban which could have been avoided with a swift apology, according to the head of the union which represents referees.
The Scot has until Tuesday afternoon to respond to a charge of improper conduct brought about by his criticism of referee Martin Atkinson's performance in Manchester United's match at Chelsea.
Alan Leighton, head of the Prospect union, told BBC Radio Five Live: "Everybody would prefer to see an apology and an explanation and then move on. In the absence of that, a charge is going to take place."
Ferguson has decided not to hold a press conference ahead of Sunday's Premier League clash with Liverpool. Unless he can persuade the FA of his innocence, he is facing a lengthy period away from the dug-out.
He already has two matches of a four-game ban hanging over him following his ill-advised comments about Alan Wiley last season, when he implied the official was not fit enough for his job.
That will be triggered if guilt is established, which would condemn him to the stands for United's FA Cup quarter-final tie with Arsenal at Old Trafford on March 12, plus the Premier League encounter with Bolton seven days later.
Punishment for his latest indiscretion would be added. Leighton does not feel referees live in fear of Ferguson's criticism.
"I don't think they fear anybody, I think they referee without fear or favour and that is absolutely right," Leighton said.
"I think there is an issue in that (Ferguson) isn't the only one - all managers need to think about what they say in terms of criticising referees. All of the referees understand that their performances will be criticised and their decisions will be criticised, and they are absolutely fine with that, not a problem.
"But when the fundamental ability of the referee to do his job is criticised - in terms of physical fitness or integrity - then that line has been crossed. If managers are going to start questioning the integrity of referees, then they can't be surprised when action is taken against them."
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