Celtic winger Aiden McGeady has accused Old Firm referee Dougie McDonald of lacking impartiality in the Hoops defeat at Ibrox last weekend. The match, which saw Scott Brown sent off for a tussle with Kyle Lafferty, finished 1-0 to the home side and McGeady is the latest to criticise McDonald’s performance.

The Republic of Ireland international may end up in hot water with Scottish Football Association for his outburst, but claimed the official’s performance was influenced by his club’s criticism of referee’s in the build-up to the Glasgow derby.

An anonymous source leaked that Celtic had held talks with SFA to express concerns over refereeing standards just four days before the match. The claims have sparked a feud between the Parkhead side and the SFA which has continued through the appeal process when the club attempted to have Brown's red card overturned.

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.

"The comments before the game might have played on his mind,” said McGeady of McDonald.

"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."

Rangers now lead Celtic by 13 points at the top of the table thanks to a 3-1 victory over St Mirren on Saturday while Celtic will face Falkirk today.