Simon Cowell's mother says Gareth Gates should win Pop Idol.

Julie Cowell reckons the 17-year-old A-level student has the star quality to make it in the pop world.

But she said her 42-year-old son Simon, one of the judges on the ITV show, had not revealed to her who he wants to win or the song the winner will release as a single.

She also told how her son was feeling the strain of being part of the series, which reaches its finale tonight when Gareth goes head-to-head with William Young.

She insisted Simon does not deserve his Mr Nasty nickname for his cruel comments to performers and says he is not like that in real life.

Julie, 76, of Ovingdean, near Brighton, said: "I think Will could do brilliantly in West End musicals. I'm sure he can have a great career there because he can sing and dance so well.

"But Gareth has really got what it takes to be a genuine pop idol. He has the look, which will appeal to all the young girls, he can sing beautifully and he is doing so well to get over his stammer."

She said: "Simon told me that when the judges heard him sing for the first time, they were all absolutely stunned.

"They were at the end of a hard day after hearing about 200 auditions. Then this boy came along with a stammer and they didn't know what to expect but his singing was just amazing."

Julie was travelling to London with her family today for the final.

She said: "I can't wait to see it. I've seen a show being recorded before and it's really exciting. Presenters Ant and Dec are so funny, especially when they dress up. Simon is the second youngest of five brothers and all the family love the show.

"They will all be glued to their television screens watching the final.

"The popularity of the show has gone beyond all the judges' expectations. I know Simon and Pete Waterman never thought it would be as big as it is.

Julie said she was worried about her son being dubbed Mr Nasty for his harsh put-downs of contestants who don't make the grade.

She said: "All the attention he's been getting is a bit frightening. But he really is quite charming and always has been. His television image is quite funny to all the family.

"He has to be tough. He knows it would be more cruel to build false hopes."

She said Simon is now considering whether to be a judge on an American version of Pop Idol.

Simon grew up in Hertfordshire and Buckinghamshire with his family and then worked in the post room at EMI when he left school.

He moved to London to make it in the music business, where he now lives in Kensington.