Madonna: Baroque aria girl?

He has already sung with Bono, Ronan Keating and the Spice Girls.

The Italian is in London promoting his concert in Hyde Park on 14 July.

He said: "You should implore her to come to my concert. It is my hope.

"Madonna has a very clear idea. She promised to come if we sing together Caro Mio Bene and I'm very interested.

"She told me in confidence. I have asked her but she has been busy - first she makes the baby and then, I don't know."

Covent Garden

The Hyde Park show takes place 10 years after his triumphant performance in the park when the rain sodden crowd included Diana, Princess of Wales, and Prince Charles.

"I will never forget to see the Princess and the Prince and all the politicians of different parties sitting in the front row and remain seated without umbrellas, as it was asked," he said.

The concert aims to raise �1m for charity to be split between the Prince's Trust and a cause chosen by the sponsor, Safeway.

The 65-year-old is to sing Tosca at the Royal Opera House in Covent Garden next and has no plans to retire.

But he doubted he would be singing at the age of 88 like his father.

"I definitely will stop before then. I will let you know after the Tosca that I'm singing here next year," he added.