The Football Association are to review Manchester United manager Sir Alex Ferguson's comments about referee Martin Atkinson after his side's 1-0 defeat to Portsmouth in the FA Cup on Saturday.

Ferguson was also highly critical of referees boss Keith Hackett for his apparent lack of action in dealing with underperforming officials.

"Managers get sacked because of things like that and he's going to referee a game next week," said Ferguson. "He (Hackett) is not doing his job properly and he needs to be assessed."

He added: "I'm assessed as a manager, players are assessed, referees should be assessed properly by the right people. That performance should not be accepted by our game."

A spokesman for the FA said: "We are aware of the comments and will be giving them consideration."

Should any action be taken against Ferguson and he is found guilty he would be fined rather receive a touchline ban.

United were aggrieved that Atkinson failed to give a penalty for Sylvain Distin's challenge on Cristiano Ronaldo.

But Portsmouth boss Harry Redknapp said: "I didn't think it (Distin on Ronaldo) was a penalty. I don't think we made a bad tackle during the game. There was only one bad tackle - and that was made by a Manchester United player (Wayne Rooney was booked for a feet off the ground lunge at Niko Kranjcar).

"I thought he [the referee] got it bang on. If it was a penalty I would be the first to say 'we got away with that one'.

"I think Ronaldo pushed it too far and I didn't see anything wrong with the challenge. Our penalty (Tomasz Kuszczak bringing down Milan Baros) was a banker penalty."