Sir Alex Ferguson has described the Football Association's disciplinary department as a "dysfunctional unit" and called for a complete overhaul of its procedures after claiming that Liverpool were given preferential treatment to Manchester United.

Ferguson was responding to the FA's decision not to punish Liverpool's captain, Steven Gerrard, for the use of his forearm on Portsmouth's Michael Brown at Anfield on Monday. "I don't think they know what they are doing," the United manager said. "But I certainly think if it was a Manchester United player he would have been done, as was the case with Rio Ferdinand. It is crazy at times. You scratch your head. Everybody scratches their heads at some of these decisions. You scratch your head but it will always be that way."

Ferguson was referring to Ferdinand's three-match ban for swinging his arm into the face of Hull City's Craig Fagan in January, a punishment that was increased to four matches when the champions lodged an appeal.

Gerrard would have been banned from Liverpool's trip to Old Trafford tomorrow if he had been found guilty of an FA charge of violent conduct and Ferguson alleged that the Anfield club historically got away with more than United. "We know that. They do all right. They are lucky like that. Maybe one day we will get lucky."

Ferguson was in one of his more outspoken moods and, as well as several thinly disguised put-downs about Liverpool's league results, including the observation that they had overachieved last season, he was irritated to learn that the fit-again Owen Hargreaves had been talking of playing for England in the World Cup.

Hargreaves has been out for 19 months with knee problems after making 25 starts since signing from Bayern Munich for £18m and Ferguson said: "I think we deserve some service first, right? He needs to get his service in. Christ, talking about World Cups? There is nothing wrong with talking about it. But he should be concentrating on United, right? And he will do that."

His main ire, however, was reserved for the FA. "I didn't expect anything to happen to Steven Gerrard," he said. "It [the FA's disciplinary department] is a dysfunctional unit. There is no consistency for a start and I didn't expect any. But there should be set rules and for years the LMA [League Managers Association] have been trying to get involved.

"There are about 20 redundant managers around who have had good experience of the game, have good knowledge and played the game. They could get involved and it would save [the FA] a fortune because God knows what it costs them down there in London.

"It costs them a fortune and what results are we getting? You could ask every manager in the league, every week, and they will tell you about inconsistency. So therefore I wonder if it's worth the managers who don't have a job taking over that department. We could have a body of four sitting every Sunday assessing the TV issues of the weekend. These guys have played the game and that's the big advantage they would have over the people doing it at the moment."

Ferguson also questioned the conduct of Liverpool's players when asked about Nemanja Vidic's record of three red cards in three games against Liverpool. "The two at Anfield were definitely influenced by the crowd and the Liverpool players. I have looked at them again. The last one was two yellow cards and I don't think they were right."

Liverpool, fifth in the league, are 15 points behind United at the top, and Ferguson said he had no sympathy for Liverpool's manager, Rafael Benítez. "I don't know what they are mired in," he said. "Their challenge last year was obviously championship form but sometimes you peak with a particular team and it's difficult to do again. Everyone expected Liverpool to be better, but they are not. The challenge for them now, along with a few others, is to get that fourth spot, which is a league of its own."

Asked if he was saying Liverpool had overachieved last season, Ferguson said: "Yes. They did very well. When they got that run going they showed form and consistency. I thought it was an exceptional season for them but that it would be difficult to achieve that again."

He described Liverpool's 4-1 win at Old Trafford a year ago this week as "an abnormal blip" but insisted he was not motivated by the prospect of overtaking them on 19 league titles. "I don't think of it that way," he said. "If we win the 19th title the most important thing will be the next one, the 20th."