Teenage heart-throb Gareth Gates, pictured, is set to take his bid for superstardom a step further tomorrow night with his own rendition of two chart-topping hits.

The Telegraph & Argus can exclusively reveal that Gareth will sing versions of Wham!'s Wake Me Up Before You Go Go and the Righteous Brothers hit Unchained Melody on ITV's Pop Idol show.

And his mum Wendy, who will be cheering her son on in the audience at the London studios, admitted it would be Gareth's most emotional performance yet.

Wendy said Gareth, 17, had chosen Unchained Melody because it was her favourite.

"He's going to sing that song because he knows how much I like it. I'm absolutely delighted he's doing it," she said.

"He told me that he would sing the song for me - I thought that was a lovely thing for him to say."

Each of the remaining four contestants have this week had to select two songs from a list of classic number ones dating from the 1950s to the present day.

They were asked to choose one ballad and one more up-tempo number for the showdown on tomrrow night's show.

Despite being a big fan of the Righteous Brothers hit, Wendy admitted that she wasn't so sure why Gareth had chosen Wake Me Up Before You Go Go for his second song.

"I'm not quite so keen on that one, but I am sure he will make it sound fantastic," she said.

Gareth was born the year eighties duo Wham! - George Michael and Andrew Ridgeley - topped the charts with the hit.

One of the biggest sounds of 1984, it stayed in the Top 20 for eight weeks.

Unchained Melody has twice been a chart smash, hitting the number one spot in 1965 and winning over a new generation of fans nearly 30 years later when it was on the soundtrack for the 1991 smash hit movie Ghost.

Gareth is hoping his performance wins over the notoriously critical judges, who have warmed to the Bradford teenager again in recent weeks, along with the thousands of viewers who have voted for him.

The East Bowling teenager will compete with Darius Danesh, Will Young and Zoe Birkett to get through to next week's round of the show. One of the four singers will be voted off tomorrow night.

Wendy was due to travel down to London last night to be with Gareth as he goes through his final preparations for tomorrow's show.

She said: "I am excited and nervous, just as I am every week at this stage. The whole competition has just become a massive thing, but Gareth is handling the pressure of the media really well."