Ferguson insists he has "always respected Mr Wiley's integrity"
The head of the referees' union wants Manchester United manager Sir Alex Ferguson banned for claiming match official Alan Wiley was not fit enough.
Ferguson has since apologised for any embarrassment his remarks after the draw with Sunderland may have caused.
But Alan Leighton, head of officials' union Prospect, told BBC Radio 5 live the apology was "half-hearted".
"A punishment should be a Uefa-type coaching ban, which is more than a touchline ban," said Leighton.
"A Uefa ban involves a ban for a greater period of time during, before and after a game."
An analysis of Wiley's fitness following the initial remarks from Ferguson after the recent 2-2 draw at home to Sunderland showed the referee's performance proved he had run more than most of the players during the game.
The Football Association has asked the Old Trafford boss to explain his comments by 16 October and, even though he has issued an apology, Leighton has criticised the manner of it.
Ferguson said he would be contacting Wiley to talk to him personally but he still left a question mark hanging over the fitness of referees in England.
"My only intention in speaking publicly, was to highlight what I believe to be a serious and important issue in the game, namely that the fitness levels of referees must match the ever increasing demands of the modern game, which I hope will now be properly addressed through the appropriate formal channels," added Ferguson in his statement at the weekend.
Leighton responded: "I think it probably exacerbates the position rather than resolves it.
"He clearly hasn't retracted his statement about Alan being unfit so it's not an apology to Alan for the main offence caused. He then widens it to question the fitness of other referees in the select group.
"He seems to be opening another can of worms, which I don't think is helpful at all."
He stated: "One of the things I've done as a result of this is to call on the employer (Professional Game Match Officials Ltd) to issue a report about the fitness of the referees, showing how fit they are.
"They have sports scientists. They don't just pass a fitness test at the start of the season.
"They are tested throughout the season, they download all of their training data and their body mass index and body fat are regularly monitored.
"They have get-togethers every two weeks where they are put through extensive training and testing. They are really fit.
"Now this issue has been raised we need to be in a position where the employer makes more public the fitness of the referees to defend them."
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