The Twitter abuse of referee Mark Halsey has been condemned as “beneath contempt” by the match officials' union Prospect.
Halsey was the victim of two abusive tweets yesterday, both of which referred to his throat cancer diagnosis in 2009.
The 51-year-old official sent off Liverpool midfielder Jonjo Shelvey and then awarded Manchester United a controversial penalty in the Barclays Premier League game at Anfield, with Robin van Persie converting the spot-kick for a 2-1 win.
A tweet posted from an account named johnwareing1 read: "I hope Mark Halsey gets cancer again and dies" while another from lfcjohn259 read: "Mark Halsey should've died of cancer."
Both tweets were met with outrage from other users of the social media site. The post from lfcjohn259 was deleted and the johnwareing1 account was removed completely.
The national secretary of Prospect, Alan Leighton, expressed his union's disgust regarding the tweets in a statement to Press Association Sport.
His statement read: "Prospect wholeheartedly condemns the unacceptable abuse aimed at Mark Halsey on Twitter. The comments made by a very small minority will be seen as beneath contempt by all decent people.
"The main concern now is for Mark and his family, who are receiving the support of his employer, PGMOL (Professional Game Match Officials Limited). Prospect will also provide any assistance as required."
Halsey returned to refereeing in March 2010, and is due to officiate the Capital One Cup third-round meeting between Southampton and Sheffield Wednesday tomorrow night as originally planned.
PGMO, which provides referees to the Premier League, also issued a statement to Press Association Sport deploring the actions of the small minority of abusive Twitter users.
"PGMO abhors any abuse of match officials whether that is in stadia or outside of it.
"Our main concern is towards Mark and his family, and as with all match officials, there is a backroom team who are there for them.
"This includes a sports psychologist, who has worked extensively with the Select Group including Mark over the past few years. Mark has already benefited from the support of all of his Select Group colleagues and they will continue to back him this week.
"None of the Select Group match officials are on social media."
Halsey showed a red card to Shelvey for a challenge on Jonny Evans but both managers had different views on the decision with Liverpool boss Brendan Rodgers also questioning the award of United's penalty.
United manager Sir Alex Ferguson said of the decision: "I thought it was a clear red card.
"I don't think he went for the ball - Jonny Evans went for the ball and got the ball - and the boy's gone in really dangerously and I don't think there's any other decision the referee could have given."
But Rodgers was adamant his side had been hard done by.
"Jonjo Shelvey, if he gets sent off, then Jonny Evans has to go as well. I think both players' feet are off the floor," he said.
"I'm sure it's never a penalty, and then obviously Luis Suarez goes up the other end and gets a toe to the ball and the defender doesn't touch the ball, and he goes down and it looks a penalty. That was out of our control."