Sugar said that he was worried about the other candidates' criticism of Siddique, that he is always "standing around, moaning all the time".
Siddique was part of the losing Team Phoenix, who were project managed by Jade Nash this week. They picked up a healthy £838.21 profit on the task, but were edged out by Nick Holzherr's Team Sterling, who earned £955.20.
Sterling were rewarded for their victory with a trip into central London and the chance to drink cocktails made by the UK Bartender of the Year.
In the Losers' Cafe, Jade appeared to take responsibility for the team's loss, conceding: "It's hard when you talk about who is accountable. I'm the PM so probably me."
Back in the boardroom, Sugar skewers Team Phoenix over their lack of strategy, low pricing and decision to split their stock 50/50 between their two selling locations.
However, Jade took Tom Gearing and Siddique back into the boardroom for a final showdown and she turned on the fridge company boss, accusing him of wasting her time on the task.
"Azhar just kept butting in on the phone and wanting to speak to me about strategy all the time, but no solutions," she told Sugar.
"When someone is not being constructive... not coming up with a solution, it actually hinders what you are doing and it actually wastes time."
Siddique was defended by Gearing and he accused Nash repeatedly of being "out of her depth", but ultimately he paid the price for not working well with his colleagues.
In his final summary, Sugar said: "Jade - I think that you show a lot of enthusiasm but I get the feeling on this particular task that you could have controlled it a little bit better.
"I think the mere fact that you brought Tom back in here when, in fact, he was a great help to you on this occasion, is a difficult thing for me to accept, to be perfectly honest with you.
"Azhar - people are saying about you that you're just standing around, moaning all the time that this is going wrong, that is going wrong, you don't seem to come forward with any solution to what should be done.
"Jade as the Project Manager, you were responsible really for the whole strategy of this task, margins, profits and location, and for that reason I'm struggling. But I do admire your enthusiasm, and on that basis, I'm going to have to say that Azhar - you're fired!"
An annoyed Siddique said in the black cab home: "I do feel robbed, I was wrong to be fired. I think there are people in this process who are playing a game, playing a strategic game, and I think they wanted me out of the process because they saw me as a threat, they saw me as one of the stronger candidates, and obviously they've got their way."
The Apprentice continues next Wednesday at 9pm on BBC One.