Mourinho voiced his displeasure at the performance of referee Mike Jones after the 0-0 draw with Hull last night.
He complained about the lack of action against Liverpool boss Jurgen Klopp after he shouted in Neil Swarbrick's face, and the leniency of Arsene Wenger's four-match touchline ban.
Mourinho out! Man United fans furious after Hull stalemate
Wed, February 1, 2017
Express Sport brings you all the best tweets as Manchester United fans call for Jose Mourinho to be axed after their draw with Hull
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Manchester United fans are not happy with Jose Mourinho after drawing with Hull
Mourinho has had to serve two touchline bans this season for his behaviour, and Hackett believes the United manager has reason to be frustrated.
He wrote in his You-Are-The-Ref column for the Telegraph: "Mourinho will have seen the incident where Arsene Wenger received a four-match touchline ban for shoving fourth official Anthony Taylor and immediately questioned why the Arsenal manager was not given a stadium ban.
Jose Mourinho was unhappy with the refereeing against Hull
"A few weeks later he then saw Jurgen Klopp get away with yelling in the face of fourth official Neil Swarbrick during Liverpool's game with Chelsea and he thinks that he would have been sent off if that had been him.
"I agree with him. I'm not sure he is being treated equally.
Liverpool boss Jurgen Klopp shouts in Neil Swarbrick's face
"Mourinho was given a stadium ban for verbally abusing a referee a couple of seasons ago, while Wenger was allowed to stay inside the stadium with an earpiece, communicating with the technical area, despite admitting his offence. Why did they not apply a stadium ban to Wenger?
"What happens is that Mourinho is left wondering where the line is with regards unreasonable behaviour and left thinking that there is a lower barrier for him than for other managers."