X Factor twins John and Edward Grimes plan to "exterminate" their nemesis Simon Cowell during their next performance on Saturday night.

The Mirror told yesterday how they will do the Ghostbusters theme, as part of a week of songs from the movies on the ITV show.

And show choreographer Brian Friedman is now working on a routine that will see them attack Cowell in a humerous way.

An X Factor source said: "Brian is working out if it is possible for Cowell to appear as a ghostly figure on stage, or whether someone can float onto the stage with a Cowell face mask on.

"The boys, dressed as Ghostbusters, will then exterminate the figure using lazers. The audience would love it and it might even bring a smile to the real Simon Cowell.

"Another idea was for Cowell to be 'slimed' but he wouldn't put up with that, and given that he is an executive producer on the show, he would veto that idea.

"But you can rest assured it will be another special performance from the twins. Many of the acts are doing ballads this week because of the movies theme, which means they won't move around too much. That leaves Brian even more time to work with the Twins and create a chaotic three minute act."

As well as rehearsing, John and Edward were busy hitting back at criticism from the likes of Cowell that they cannot sing.

John, 18, said: "I know people are saying we can't sing, but we're singing current songs and we're trying to show that we're current artists.

"The thing is, we can't come out and just wail these massive ballads.

"We want to be doing something people have never done on a show like this before."

Speaking in OK! magazine, his brother Edward added: "You don't see artists nowadays just singing, they are dancing too and showing that they can actually put on a live show. People don't want to spend 80 quid on a ticket to see someone just standing there singing."

Bookies yesterday admitted they are now fearing a twin win, and they have cut their odds again from 10-1 to 8-1 on winning the compeition.

"We have been running scared, since we heard that the twins were singing 'Ghostbusters', it is the perfect silly song and we think Jedward will survive again," said Hill's spokesman Rupert Adams.

And just when you thought they couldn't get any bigger, Jedward have an unlikely new super fan - pop babe Britney Spears.

The Toxic singer has been watching clips of the Dublin duo on youtube and was in fits of laughter at their wacky take on her Hit Me Baby One More Time anthem.

Britney roared with delight when she watched the spikey-haired teens attempt her dance moves in red leather jump suits.

And she is so taken with the lads that she has begged to meet them the next time she is in the UK.

A source close to Britney revealed: "She has been watching all their performances on the internet - she is a huge Jedward fan.

"Britney thinks it's hilarious to see them up there singing her song and doing all the dance moves.

"She wants to meet them and has even suggested getting them on stage with her when she tours again for a bit of fun.

"Britney is supporting them big time and wants them to go all the way and win the show."

"We have been running scared, since we heard that the twins were singing 'Ghostbusters', it is the perfect silly song and we think Jedward will survive again," said Hill's spokesman Rupert Adams.

And just when you thought they couldn't get any bigger, Jedward have an unlikely new super fan - pop babe Britney Spears.

The Toxic singer has been watching clips of the Dublin duo on youtube and was in fits of laughter at their wacky take on her Hit Me Baby One More Time anthem.

Britney roared with delight when she watched the spikey-haired teens attempt her dance moves in red leather jump suits.

And she is so taken with the lads that she has begged to meet them the next time she is in the UK.

A source close to Britney revealed: "She has been watching all their performances on the internet - she is a huge Jedward fan.

"Britney thinks it's hilarious to see them up there singing her song and doing all the dance moves.

"She wants to meet them and has even suggested getting them on stage with her when she tours again for a bit of fun.

"Britney is supporting them big time and wants them to go all the way and win the show."

Despite a huge internet hate campaign and Simon Cowell's negative comments, Jedward have become a massive hit with viewers on the show with their odd-ball routines and outfits.

Their mentor Louis Walsh believes the boys can go all the way and win the competition.

He said: "Last weekend's performance was fantastic - and they are going to be even better this Saturday.

"They keep upsetting the odds and surprising everyone. I think they can win this show."