Celtic's Aiden McGeady has accused referee Dougie McDonald of lacking impartiality in Celtic's Old Firm derby defeat at Ibrox.
In an outburst which is almost certain to land the Republic of Ireland winger in trouble with the Scottish Football Association, McGeady claimed McDonald's performance had been influenced by his club's criticism of officials in the build-up to last Sunday's game.
Just four days before the match with Rangers, an anonymous Celtic source revealed the Parkhead club had met with the SFA to express concerns about refereeing standards.
The claims have sparked a running spat between the Hoops and the SFA, which intensified when McDonald sent off Scott Brown in the 1-0 defeat at Ibrox.
This week has witnessed a series of controversial statements from Celtic in response to the red card and McDonald's refusal to rescind it — but McGeady's claims are arguably the most inflammatory.
He said of McDonald: “The comments before the game might have played on his mind.
“It's safe to say he wasn't impartial the other day. Of course, it didn't look like a red card for Scott Brown.”
Celtic were also upset McDonald failed to send off Rangers defender Madjid Bougherra for persistent infringements.
Asked if Bougherra should have been shown a second yellow card, McGeady said: “Yeah, of course.”
Pressed further on the official's overall performance, the winger said: “If I told you, I would get into trouble.”
McGeady also jumped to the defence on under-fire boss Tony Mowbray.
McGeady added: “I'd like to see the manager given time. Eight or nine months isn't long enough to stamp his authority on the club.
“Celtic will always be judged on titles and if we don't win it this season a lot of people won't be happy with him and the team.
“There may be calls for him to be sacked or resign but I would like to see him stay.”