DEFIANT Ally McCoist today vowed to fight on as Rangers boss despite furious supporters calling on him to quit.

The Ibrox gaffer saw his side throw away a two-goal lead to lose 3-2 to part-time Alloa in last night's Petrofac Training Cup semi-final.

But when asked if he would consider resigning after the worst result of his managerial career, he replied: "No."

Instead McCoist - famous for saying: "We don't do walking away" at the height of the club's insolvency crisis in 2012 - slammed his players for a "lack of professionalism".

And he indicated he will be having stern words with his squad in the days to come.

Second-half strikes from Kenny Miller and Dean Shiels had put Rangers 2-0 up at the Indodrill Stadium with only 17 minutes to go.

But they then allowed Greig Spence and Ryan McCord to pull Alloa level before ex-Celtic youth star Spence grabbed a sensational last-minute winner.

And that prompted a section of Gers fans to heckle McCoist for the second time in three games.

The club legend looked shell-shocked after the defeat to the minnows, who they have failed to beat in three meetings this season.

But the Rangers manager stressed that he remains determined to lead Rangers back into the Premiership.

Asked if he would think about quitting, McCoist insisted: "No, I'm too concentrated on the game here.

"I share the fans' disappointment. They are entitled to a few choice comments, there is no doubt about that.

"But there's a long way to go in the season and I will fight tooth and nail to get the club back to where we belong.

"I'll sit down with the boys and go through this game. It won't be a pleasant meeting but it has to be done."

McCoist slammed his team for surrendering their two-goal lead against the part-timers.

He blasted: "It was a lack of professionalism to not see the game out from 2-0 up. I'm not sure it was a lack of character, but it was definitely a lack of professionalism.

"We switched off at a couple of crosses, lost markers during attacks and turned our backs at set plays. We let them take a quick throw in for the second goal and it was an easy finish at the back post.

"The first goal looked to be a free header inside the box. Players have to take responsibility to do their job and pick up people."

The stunned boss continued: "I didn't say much to the players after the game but I'll save it for the next couple of days.

"I registered my disappointment but we'll sit down in the next few days and have the full autopsy of the game.

"We've gone from a terrific performance on Sunday when we were comfortable winners against Kilmarnock, a team from the top flight, to showing a lack of professionalism after going 2-0 up. To not make a cup final after being two ahead with 20 minutes to go is very disappointing.

"But after that we took our foot off the ball. We lost some really sloppy goals and we got what we deserved."

Rangers midfield ace Lewis Macleod was stretchered off in the first half after appearing to suffer a hamstring strain.