Dermot Gallagher will be demoted from the Premiership's list of referees following his failure to dismiss Ben Thatcher for his horrific challenge on Pedro Mendes.

The Oxfordshire referee opted to caution the Manchester City defender for felling the Pompey midfielder with a forearm smash on Wednesday night.

By doing so, Gallagher implied that he had seen the challenge but still believed that a yellow card was sufficient despite Mendes being knocked unconscious.

While the decision has prompted widespread incredulity and outrage, it is the

unequivocal refusal of referees' chiefKeith Hackett to defend Gallagher's failure to dismiss Thatcher that spells the end of his Premiership career.

Speaking out in unusually harsh terms against a member of his refereeing team, Hackett told The Daily Mail: "Having looked at the replays I've been disappointed with some refereeing decisions. I've already taken action in terms of selection for forthcoming games. The criteria for top level is that these are made on the basis of performance.

"Everyone wants to get off to a good start in a season and referees are no different. You will always get an error but in some of the opening games there were clear errors I can't defend."

Wednesday's appearance at the City of Manchester Stadium is thus likely to be Gallagher's first and last in the Premiership during his final season as a referee. At 49, he has already passed the cut-off retirement age but was awarded a 12-month extension last year.

The official is no stranger to criticism. Gallagher has twice previously been demoted - for failing to dismiss Arsenal defender Steve Bould for a professional foul in 1998 and only cautioning Robbie Keane in 2001 after he slapped David Beckham - although he escaped censure for red-carding Arsenal's Gilberto Silva at Newcastle last December for two innocuous challenges.