Geri opted for the less is more fashion option

Jenny Frost stunned the prince by holding up an I Love Atomic Kitten T-shirt and giving him a hug for photographers.

Other shocks at the Capital FM event in London's Hyde Park saw former Spice Girl Geri Halliwell perform in a skimpy leotard in front of the 100,000-strong crowd.

Not to be outdone American trio Destiny's Child appeared in trademark skin-showing outfits.

The girls had covered up by the time they met the prince.

Profits from the concern go to Prince Charles' Prince's Trust charity, which supports young people in finding work.

Spice Girl Emma Bunton announced she was to become an ambassador for the Prince's Trust.

She made the announcement at the party as she cut a birthday cake baked for the charity's 25th anniversary celebrations.

She was one of several celebrities to enlist - the Prince of Wales had already convinced Hear'Say singer Noel Sullivan to become an ambassador.

The 100,000 music fans who had descended on the park did not allow the rain showers dampen their spirits.

Other headline acts included Hear'Say, who performed their two number one hits.

Ricky Martin makes his second appearance at the party

Afterwards they got to meet the prince, who told the band his sons had watched them on television.

Singer Myleene Klass said said: "Prince Charles was really witty and light-hearted. He was great to talk to."

Kicking off the afternoon was Latino star Ricky Martin, bringing his brand of sunshine pop to the overcast proceedings.

Screams

Capital FM presenter Chris Tarrant introduced the star as he launched into his familiar hits such as Living La Vida Loca, to a backdrop of delighted screams from the audience.

Other acts who hit the high notes included Shaggy, Wheatus, Eddy Grant, Craig David, A1 and Ronan Keating.

Prince Charles shares a joke with Hear'Say

Atomic Kitten's bold move was reminscent of Geri Halliwell's stunt four years ago when she pinched the bottom of the future king as he greeted the Spice Girls.

Earlier, when the Atomic Kitten singers were asked whether they would be copying Halliwell's example, Frost said: "We wouldn't do anything like that with the future King of England. It would be so disrespectful."

But she obviously had a change of heart when she whipped out the tight-fitting T-shirt.

Craig David sported a new hairstyle

Prince Charles met many other stars while at the concert, including pop veteran Eddy Grant who had performed his rekindled hit Electric Avenue.

He also took time to pop into the ITV studio to meet TV presenters Ant McPartlin, Declan Donnelly and Cat Deeley to receive a silver disc to celebrate 25 years of the Prince's Trust.

Ant and Dec had previously gone to the prince's home for a rare interview, in which he revealed his fondness for acts such as Elton John, Dire Straits and Catatonia.