X Factor judges Gary Barlow and Tulisa Contostavlos were locked in peace talks last night after he accused the N-Dubz star of having "fag-ash breath" in front of millions of viewers.
Barlow has apologised for the remark he made on last night's ITV1 programme as show insiders revealed the pair spent time alone in a dressing room discussing their spat after filming finished.
A show source said: "They were locked in a dressing room for peace talks after the show; just the two of them. Gary apologised a lot. Tulisa was angry but eventually she accepted his apology.
"Gary feels really, really bad about what he said. It was speaking without thinking in the spur of the moment and he didn't mean it."
Barlow, 41, made the comment after Contostavlos criticised the song choice of his act Christopher Maloney.
The Take That singer blurted out: "Tulisa, I don't know what's offended me more: what you said or the fag-ash breath."
Moments later Contostavlos interrupted host Dermot O'Leary and said: "Just a note for Gary: lay off the red wine because I can really smell that as well."
Offering an apology on ITV2's The Xtra Factor, Barlow said: "Can I apologise to Tulisa; I mean it. You have the freedom to be as personal as you like to me for the rest of the series. Insult me."
Contostavlos then told the X Factor spin-off show that Barlow had once said he "loved" the smell of cigarettes because it reminded him of the days he used to smoke.
One of the remaining X Factor acts will be voted off in tonight's results show on ITV1 at 8pm.
But singer Lucy Spraggan will automatically go through to next week's programme after being unable to perform due to illness.