Simon Cowell wants Cheryl Cole to ditch her dancer boyfriend Derek Hough – for the sake of her career.

The TV mogul told Derek, 25, the Girls Aloud singer needs to focus on her work, it has been claimed.

Simon, 50, laid out his thoughts for Derek in a man-to-man chat over dinner at his London mansion recently.A close friend of Derek’s said last night: “Derek said Simon was friendly enough, but very firmly told him exactly what he thought.

“During the dinner Simon told Derek, ‘It’s nothing personal, I just don’t think Cheryl should be spending so much time with you so soon after her marriage break-up.’

“After the dinner Derek said to me, ‘I just could not thaw him out. He is just so firm about where he stands.’”

Simon became Cheryl’s career mentor after he hand-picked the 27-year-old Geordie to replace Sharon Osbourne as a judge on X Factor in 2008. He has also supported her following the break-up of her marriage to cheating soccer star Ashley Cole.

Derek’s pal claimed: “Derek told me Cheryl respects Simon more than anyone else and she knows it is down to him that she is where she is today.

“She thinks he is wise and emotionally intelligent, which is why Derek is so scared that Simon’s opinion could hurt them in the long run.

“Simon told Derek he didn’t want to be mean to him, he just wanted to make sure he did everything to safeguard her happiness and career.”

The dinner took place while Cheryl was sick with malaria after a trip to Africa with Derek.

A spokesman for Cowell said last night: “Simon is very happy with anybody that will make Cheryl happy.

“Simon only cares about her health. He wouldn’t dream of telling anyone what to do in their private relationships.

“He just wants her to be happy and healthy, and that’s all that matters.

“There is absolutely no way Simon would be advising her and him about her private life. He was worried about her health and is very relieved she seems to be well again.”

Meanwhile, contestant Annastasia Baker’s father hit out after Cowell compared her to a “tranny”.

Annastasia, now 21, had a meltdown on the show two years ago but returned to try again.

As she belted out Proud Mary, Cowell said: “This is like one of these terrible Tina Turner tribute acts. I’ve seen trannies do better versions.”

And he said her image was awful. But dad Ian said of Saturday night’s show: “Simon used some harsh words. I don’t think what was said was fair.

“Annastasia spent a lot of money on her image and had poured time and effort into it.

“No father wants to hear his daughter being called a tranny, especially after everything she has been through with the show in the past.”

Annastasia made it throught to bootcamp after Cowell gave her a chance to perform Adele’s Make You Feel My Love.

The X Factor set new records at the weekend with a peak of 11.8million tuning in for the series’ second show. Saturday’s 75-minute show pulled in half of all TV viewers at 8.30pm – and averaged 9.8milllion.