Katherine Jenkins is set to become the Simon Cowell of the opera world.

The Welsh diva is a judge and mentor on new ITV reality show Popstar to Operastar, and realised that out of the panel – which includes Laurence Llewelyn Bowen and Meatloaf – she is the toughest judge.

Katherine said: “I’m learning that apparently I’m the tough one, which I didn’t think I was.”

She explained: “I used to be a singing teacher before I got my record contract so I have always said that I wanted to go back and do some teaching and no one ever believed me, but when this got offered to me it was the perfect thing and I think maybe I slip back into my teaching mode.”

The 29-year-old soprano also revealed she thinks learning opera will help the pop stars when they return to their day jobs.

She said: “I’m really enjoying going back to the technical stuff with them because a lot of the singers have never really had a technical singing lesson before, so they’re learning how everything works and I think that’s only going to help them in the future when they go back to the pop world. They’ll have tools which they can use.”