Hearts manager Craig Levein has defended his right to criticise match officials after branding Bobby Madden "abysmal" following Sunday's defeat by Rangers.

Levein claimed Hearts were playing against 13 men after being frustrated over the failure to flag Alfredo Morelos offside ahead of the Colombian's winner.

Former referee Steve Conroy described Levein's comments as "derogatory and demeaning" and claimed criticism of officials was becoming too personal.

But Levein disagreed.

"I'm angry about what happened and I'm probably even angrier when you get ex-referees who come out and just talk rubbish," he said.

"To say I had a personal attack on Bobby. I wasn't talking about Bobby as a person, I think he's a great guy. But as a professional performance, that's completely different. And I think I am entitled to do that."

Levein added: "I criticise my players, I criticise myself, which I have done  recently. So if someone makes a blatant mistake, surely I'm allowed to say?

"And if it continues to happen again and again and again, for the seventh time this season, then surely I'm allowed to say?

"You're not allowed to speak to the referees, You can go in 15 minutes after the game. By then it's too late."

Levein has also given up on consulting John Fleming, the Scottish Football Association's head of referees.

"All I'm asking for is for people to do their jobs properly," he said. "It has a huge impact on me as a manager, and my livelihood.

"So if someone makes a blatant mistake, especially if I have already spoke to the referees' supervisor and he has told us what to do. He told us what to do and we did it, and they still get it wrong.

"When you look at that situation, how's it possible he can get that wrong?

"It's a pretty blatant mistake, especially when the guy in charge of the referees is telling us that if we hold the line on the 18-yard line, that's much better for his officials.

"We have had another six of those already this season that they've got wrong. So this isn't me talking about it for the first time. (Assistant manager) Austin (MacPhee) has been talking to John Fleming about this situation and they are continually getting it wrong.

"I'm finished. What's the point? After that, I'm finished speaking to John."

The defeat was Hearts' fourth in a row and they now travel to face a St Johnstone side who have taken 16 points from their last six matches.

Saints will leapfrog Hearts in the Ladbrokes Premiership if they win but Levein is hopeful that Sunday's performance marked a watershed.

"I was hoping Sunday that we could get something which becomes the foundation for us improving again," he said.

"I think we might have got enough from the performance to do that, and Wednesday night will tell us.

"I was pleased with the energy and determination and all the things we did at the weekend, and if we had been a wee bit better with the final pass, we could have had more opportunities."