The 11 remaining X Factor contestants have tackled rock songs in the latest round of the live finals – but the show was punctuated by heated discussion from the judges as tempers threatened to flare.

The dramatic show saw the quartet disagreeing over performances from some of the remaining finalists, but also coming to blows over allegations that Misha B – who closed the show with a stirring rendition of Prince’s Purple Rain – had been bullying the other contestants backstage.

“I think you are very competitive,” Tulisa told her, “and I’ve seen a different side to you backstage, in some ways you being so feisty can come across as quite mean to certain contestants and I’ve been told by a few this week there’s been a few mean comments towards them.

“I’m not putting you down,” she added, “but take that feistiness and energy when you get on the stage and leave them all behind.”

Gary Barlow defended the singer saying he did “not care what goes on backstage”, while her mentor Kelly Rowland also joined the debate, adding, “We leave things backstage, backstage”. But Louis sided with Tulisa, saying one of his acts had “complained” about the 19-year-old’s behaviour.

Elsewhere Sami Brookes also came in for criticism and left the judges arguing after Gary described her rendition of Cher’s If I Could Turn Back Time as “totally boring”.

“We are trying to find someone who can sell albums, singles, cds, someone who can be a star. After that performance tonight, you’re going to be none of the above!” he told her.

Mentor Louis hit back, pointing out that Sami had been ill in the run-up to the show.

“She’s had a terrible day, I’m not looking for a sympathy vote but she pulled it out of the bag, that was a very powerful performance,” he said.

Rhythmix also caused disagreements between the judges – not for their performance, which won praise from the judges, but from a song choice of Kesha’s Tik Tok combined with the Salt n’Pepa hit Push It.

Louis, Kelly and Gary all pointed out to Tulisa that the track was not in fact rock, although she was quick to defend her decision. “It’s rock week, not rock song week,” she said. “If you didn’t know it was Kesha and you heard it tonight it would be commercial rock.”

And Frankie Cocozza fell foul of mentor Gary Barlow, who blasted his performance from the previous week.

“When I decided to sit in this seat, there was one thing I promised myself I would never do and that was lie,” he said. “I lied for you last weekend and said your performance was good and it wasn’t – it was awful. You deserved to be in the bottom two.”

However Gary was kinder about Frankie’s rendition of Primal Scream’s Rocks, saying, “To me, that was a comeback. Not an incredible one but a comeback to who you should be.” Louis also spoke out in favour of the teenager saying, “I think I did the right thing saving you last week but I think you’re a little over-confident.”

And other acts did manage to impress the judges, including Marcus Collins, who kicked off the show singing Lenny Kravitz’s Are You Gonna Go My Way and wowed the panel with his performance.

“What a brilliant opening to the show,” Louis said, “You sang, you smiled, you performed,” while Tulisa agreed. “You absolutely blew me away,” she told him.

Gary, meanwhile, was impressed with Janet Devlin’s Celtic-fused rendition of the Guns n’Roses classic Sweet Child Of Mine. “That was simply beautiful and gorgeous,” he said. “Well done.”

Sophie Habibis also fared well with a slowed-down version of Bon Jovi’s Living On A Prayer, while Craig Colton was once again a hit with the judges, this time singing Oasis’ Stop Crying Your Heart Out.

This time it was Tulisa’s turn to question the genre, saying, “It was an amazing ballad but it didn’t feel like a rock song,” but Kelly disagreed. “That was definitely a rock song,” she told Craig. “So proud of you, great performance tonight.”

Kitty Brucknell – who played piano on her rendition of Live And Let Die – also went down well, as did The Risk, singing the Gnarls Barkley chart-topper Crazy, although the performance was somewhat hampered by band member Ashley J Baptiste contracting laryngitis.

Nonetheless the judges loved it. “You totally pulled it off,” Gary said. “There’s a great work ethic in this band that a lot of the other contestants could learn from.”

And Tulisa was full of praise for Kitty’s performance. “I can never find anything bad to say about you,” she told the 26-year-old, “you’re an amazing artist.”

And Johnny Robinson received a huge response from the audience for his rendition of The Darkness’ I Believe In A Thing Called Love – and the judges were similarly enthusiastic.

“You’re my guilty pleasure,” Kelly told him, while even Gary Barlow – who has openly expressed doubts about Johnny in recent weeks – gave him the thumbs up. “Johnny,” he said unexpectedly, “I really enjoyed that.”

The results will be revealed on Sunday evening’s show, with one more act set to depart.