Former Premier League referee Graham Poll has backed Rafael Benitez's claim that Sir Alex Ferguson receives lenient treatment from the Football Association.
Liverpool manager Benitez blasted his Manchester United counterpart on Friday, alleging Ferguson does not get punished sufficiently for his sometimes outspoken criticism of match officials.
"During the respect campaign, and this is a fact, Mr Ferguson was charged by the FA for improper conduct after comments made about Martin Atkinson and (referees' chief) Keith Hackett," Benitez said.
"He was not punished. He is the only manager in the league that cannot be punished for these things.
"How can you talk about the respect campaign and criticise the referee every single week?"
Poll was considered the Premier League's top official until his retirement at the end of the 2006-07 season.
He enjoyed a good relationship with Ferguson, who even phoned Poll to offer him support in the wake of his gaffe at the 2006 World Cup, when he showed Croatia's Josip Simunic three yellow cards.
But the former referee agrees with Benitez's suggestion that the United boss receives preferential treatment from FA disciplinary chiefs.
"Rafa Benitez has articulated what referees have been thinking for years - that Sir Alex Ferguson can say what he wants about them and the FA will allow him to get away with it," he told the Daily Mail.
"The authorities could point to Ferguson's two-match ban imposed earlier this season as proof that he is not out of reach of their disciplinary department, but that was for marching onto the field after the 4-3 win over Hull and for comments made directly to the referee, Mike Dean, who in reporting the misconduct forced the FA's hand."
An FA spokesman said Benitez's comments would be reviewed "in their full context" next week before any decision is reached on whether to take action against the Reds boss.