The call comes after the recent disciplinary case in which Sir Alex Ferguson was given a four-match touchline ban (two of which were suspended) and a £20,000 fine for improper conduct. This followed a personal attack on the fitness of referee Alan Wiley.

While recognising that the FA Commission of Inquiry has made a final decision on the punishment in this case, Prospect has called for stronger action if there are similar unsubstantiated personal attacks on referees in future.

National Secretary, Alan Leighton said: “Unwarranted and untrue attacks on referees damage the hard-earned reputation of our members, call into question their integrity and damage the image of the game by suggesting that the referees are incapable of doing their job.

"Referees understand and accept that their decisions will be questioned, but personal attacks are unacceptable.”

Prospect is calling for clear guidelines to be drawn up for managers and for it to be made clear that breaches will be severely punished.

Such punishment should include a UEFA-style stadium ban in which the manager is isolated from the team for a period before, during and after the match for a number of games.

Leighton emphasised that unwarranted public attacks from managers could easily lead to a loss of confidence by clubs in the referee, which could lead to the loss of the referee’s job.

Furthermore personal attacks damage the respect that referees need and deserve and make it more difficult to attract new referees to the game.

Prospect has told the FA that if more severe penalties are not forthcoming it may well be the case that a referee decides to take a case for defamation in order to protect their reputation.

Leighton said however: “It would almost certainly be the death knell for the career of any referee who took a defamation case against a manager as their position could be compromised.

"Given that recourse to the law is not a realistic proposition for an official who wishes to continue to referee it is even more imperative that the FA is prepared to administer severe disciplinary penalties where managers make untrue personal attacks on officials.”

Leighton also confirmed that Alan Wiley would not be pursuing a case for defamation against Sir Alex Ferguson.

Wiley said: “Although I was bitterly disappointed about the personal attack on me I want to put this behind me and continue to concentrate on my refereeing.”

Leighton added: “Prospect adopted a policy when we started representing referees four years ago that we would not make public comment on every criticism made by ex-referees or managers.

“The seriousness of the recent attack forced the union to depart from that policy. We will, however, continue to defend members where their professionalism is publicly questioned.”