Halliwell and Evans kept tongues wagging over their reported relationship - by leaving Evans' house in Knightsbridge, London together early on Friday morning.

Halliwell, 27, clutched her Shih-tzu dog, Harry, and smiled at photographers as she climbed into a waiting Mercedes.

Chris Evans faces the press with a matching dog

Evans, 33, who presents the breakfast show on the station he owns, Virgin Radio, joined her - carrying a matching dog.

The former Ginger Spice appeared on his show just after 0900, and Evans took a call from an young listener called Dominic.

"He wanted to ask me a question, and I said I'd refer it to you," Evans told Halliwell.

Dominic asked her: "Is Chris Evans your boyfriend?"

"He's alright. Do you think he'll do for me?" she said.

"Do you love him?" he replied.

Evans said: "You should be on Newsnight... if that's what you think, then yes, I wouldn't like to argue with you."

Teased listeners

Earlier, Evans teased listeners to his breakfast show by playing Joe Jackson's 1979 hit Is She Really Going Out With Him?

At the end of the show, Evans played Halliwell's single Lift Me Up, to which she joked: "Is this what I have to do to get my record played?"

Halliwell is currently involved in a chart battle with her former Spice Girls colleague Emma Bunton, whose collaboration with dance act Tin Tin Out, What I Am, is 5,000 sales behind Lift Me Up.

Emma Bunton: Singles rival claims Evans wanted a date too

It has been suggested the relationship is a just a promotional trick - the two share a public relations company, Freud Communications.

On air, Evans said: "Apparently, it's all a publicity stunt."

"If that's what they're saying, it must be true," Halliwell replied.

The show ended with a spoof marriage ceremony, with the couple pledging to "get their names in the papers".

The relationship dominated Friday's UK tabloids - with The Sun quoting Emma Bunton as saying Evans had phoned her nine times last week to ask for a date.

Meanwhile, The Express quoted the founder of Freud Communications, Matthew Freud, as saying: "Everyone is getting very excited about two independent people spending a bit of time together.