Sir Alex Ferguson, the Manchester United manager, and his assistant Carlos Queiroz have been charged with improper conduct by the FA. The charges relate to comments made following Manchester United's FA Cup defeat by Portsmouth last month.

Ferguson's charge concerns comments about Martin Atkinson, the match referee, and Keith Hackett, the Professional Game Match Officials (PGMO) general manager. Queiroz's charge relates to comments about Atkinson. Both parties have until April 17 to respond to the charge.

Speaking after Sulley Muntari's penalty gave Portsmouth a shock victory at Old Trafford, Ferguson felt United had earlier had a blatant spot-kick denied when Cristiano Ronaldo was blocked by Sylvain Distin. "It's absolutely ridiculous," The United manager said of Atkinson's decisions. "I cannot explain it. Managers get sacked because of things like that and he's going to referee a game next week."

Referring to Hackett, Ferguson said: "He is not doing his job properly and he needs to be assessed. I'm assessed as a manager, players are assessed, referees should be assessed properly by the right people. That performance today should not be accepted by our game."