Robbie Williams asks Michelle McManus to duet on tour

Robbie Williams is set to embark on a European tour at the end of May

Robbie Williams has invited Scottish Pop Idol winner Michelle McManus to sing a duet with him on the first date of his tour in Edinburgh.

The Rock DJ singer will embark on a highly-anticipated European tour which starts in Murrayfield on 31 May.

McManus, who won the televised singing competition in 2003, was interviewing Williams on her Afternoons show on BBC Radio Scotland when he surprised her with the invitation.

He asked her: "Would you like to come and sing with me in Edinburgh?"

Michelle McManus spoke to Robbie Williams after she won Pop idol

She replied: "What, sorry? What was that?"

Williams repeated his question and McManus, from Glasgow, can be heard starting to cry.

"Is this a joke?" she said. "For goodness sake, yes!"

"Let's do it," said Williams. "We'll sort out what song later."

The singer is set to perform some of his most popular songs on tour including Angels and She's the One, as well as new songs from his recent biopic.

He has previously performed duets with the likes of Kylie Minogue, Nicole Kidman and Taylor Swift.

Better Man tells the story of Robbie Williams and his rise to fame - but he is portrayed by an anthropomorphic chimpanzee.

The film was released in December and depicts the early days of Take That as well as his struggles with drug addiction and mental health.

McManus told BBC Radio Scotland's Drivetime programme that she assumed Williams was going to ask her for food recommendations in Edinburgh.

"At no point ever in my wildest dreams did I think he was about to ask me what he did," she said.

"I cried a lot after it happened. It's the enormity of being onstage in Murrayfield in front of about 70,000 people with Robbie Williams.

"But it's also the magnitude of the kindness. Robbie has been so incredibly kind to me on so many different occasions even though he's such a megastar."

Robbie Williams starred in his biopic Better Man which came out last year

McManus said she got to know Williams in the early 2000s after she won Pop Idol.

"Robbie had just done Knebworth and he was absolutely huge with a solo career," she said.

"He was getting a lot of really horrible stuff written about him in the press. As soon as Pop Idol came along, I got a lot of that as well.

"It was so intense at the time about how unattractive I was, about how overweight I was. He was a huge fan of reality TV and noticed that we were both getting a lot of column inches."

McManus said Williams reached out to her after her time on Pop Idol with some advice on dealing with the negativity.

She added: "I cried a lot with him at the time and it never left me because he gave me some great advice and it really helped me get through that initial period."

Robbie Williams has performed duets with the likes of Kylie Minogue, Nicole Kidman and Taylor Swift

When asked what she would like to sing with him, McManus said: "That man could hand me the phone book and I'd sing it for him, I don't care because it's Robbie Williams.

"Obviously I want to Lulu it right up - but I don't think he'll do Relight My Fire because why would he? With the back catalogue that man's got, I'm not going to ask him to whip out a Take That number.

"I'll give it my best shot. He knows I'm a big belter."

She told BBC Scotland that it was especially meaningful to sing in front of a Scottish crowd with someone who has been "really important to me throughout all of my career".

In 2014, McManus was invited to sing with Rod Stewart at the Hydro in Glasgow to celebrate 50 years of the Lisbon Lions - the Celtic team that won the European Cup in Portugal in 1967.

She also performed alongside Susan Boyle for Pope Benedict XVI during his visit to Glasgow in 2010.

But she added: "To get to this point 22 years after I won the competition, this is probably the biggest thing I've been asked to do.

"I'm still in shock. My heart is bursting."