Sutton has become quite the divisive character in Scottish football of late for his direct approach on BT Sport.
He angered Rangers fans last month by calling the club’s centre backs “horrendous” after the Ibrox side drew 1-1 with Kilmarnock.
After calling into the Radio Clyde programme, Sutton was asked by host Gerry McCulloch whether he made such comments to be deliberately confrontational. The ex-Celtic striker responded by heavily criticising Johnstone, whom he viewed as someone afraid to speak his mind, particularly about his former club.
Sutton said: “I form an argument. I think about what I do. I work for a company in BT that is deadly serious about Scottish football. We talk about the big points and we want to encourage debate. Do we get everything right? Absolutely not. When you’re a pundit you’re there to be shot at.
“Derek Johnstone made comments about me the other day about deliberately trying to cause controversy. I work in the media now and you’ve got someone next to you who’s an embarrassment to the media profession. He’s an apologist, he’s a charlatan, he’s a Rangers puppet. He’s a cheerleader, that’s what he is.
“I know that everyone is allowed their opinion, but this is a guy that, through the Craig Whyte era, Charles Green, Ally McCoist, he’s still backing Rangers. I can go home and look in the mirror and say at least I’m trying to do my job properly.”
Johnstone fired back, saying: “Listen, you’ve had your five minutes of nonsense. The one thing we have in life is choice. The choice for me now is when I’m watching the television and I’m watching a game on BT, I’ll turn the sound down because I get absolutely nothing from yourself except negativity. You have no respect for your fellow footballers whatsoever.”
Sutton later called Johnstone a “party political broadcaster”.
Johnstone said he was “disgusted with himself” for even talking to Sutton.