Professional players chief Damian Hopley believes that England captain Martin Johnson's contentious Rugby Football Union disciplinary hearing has set "a dangerous precedent".

Both Premier Rugby Partnership - the joint venture between Zurich Premiership clubs and the Professional Rugby Players' Association - and Leicester have written to the RFU, requesting appeals against the jurisdiction and procedure of Thursday night's hearing in Bristol.

The letters are currently being considered by Twickenham top brass.

Johnson received a three-week ban for punching Saracens hooker Robbie Russell in a Premiership game two weeks ago.

He was summoned by RFU disciplinary officer Robert Horner on the grounds of 'exceptional circumstances,' despite match referee Dave Pearson having yellow-carded him immediately following the dust-up that left Russell requiring six stitches to a cut beneath his left eye.

PRP, representing the interests of Premiership clubs and Premiership players, believes the match referee should be the sole judge of fact and laws on the field of play.

They also claim that the RFU should only call a disciplinary panel for citing purposes or bringing the game into disrepute.

"While physicality is an integral part of the sport, violence is never acceptable, and we are not condoning Martin's actions in this incident," said Premier Rugby Partnership acting chief executive Howard Thomas.

"However, the decision should remain with the referee, and the only exceptional circumstance in this instance is that it involved the England captain, albeit while representing his club, resulting in a media furore.

"PRP feels obliged to intervene on this issue since it sets a precedent that affects the whole of the management of professional rugby in England."

And PRPA chief executive Hopley added: "This sets a dangerous precedent with the position of the referee being undermined.

"We can't allow this to remain unchallenged, or else who knows what will happen to the future of the game.

"It is absolutely fundamental that the power remains with the referee and his officials who are on the pitch at the time, unless the circumstances are truly exceptional."

Johnson, who is currently banned until March 15, has yet to decide whether or not he will appeal against the suspension.

He has 14 days in which to lodge a protest, and at the moment is ruled out of England's potential Lloyds TSB Six Nations title decider against France in Paris next Saturday.