Sunderland boss Roy Keane has slammed the Premier League's 'Respect' campaign for referees as a "PR stunt".
He said: "We should be trying to respect the referees anyway, we don't need a PR stunt to try to do that.
"I know there was a meeting yesterday with the LMA and the managers - I declined the offer to go.
"It wasn't a great space, so I decided not to go after my disagreement with officials over the last few weeks. It is very difficult, I have to say, and the referees have got a difficult job. I have said that on more than one occasion.
"But this idea of sitting down and talking about it, I am not sure how much good it is going to do. But having said that, we have to keep trying to find a positive way of getting around it.
"Officials will always make mistakes and that has not been a problem. The problem I have had is the big mistakes always seem to go against us. Football is an emotional game, we shouldn't forget that, and we get frustrated with it."