Nicole Scherzinger with Formula One driver Lewis Hamilton. Photo: Daniel Leal-Olivas/PA Wire

Former Pussycat Doll Nicole Scherzinger has revealed her on-off relationship with Formula One driver Lewis Hamilton is back on track.

The pair has reportedly suffered a number of splits since they started dating in 2007, but things appear to have been running smoothly in recent months.

She told The Sun’s Fabulous magazine: “Uh huh, he’s a lucky guy! Yeah, things are good. We just had a nice little holiday in California. It’s a great place to break out of your shell.”

But when asked if their relationship would now be more stable, she replied: “Oh, I have no idea. How in the world am I supposed to tell you that? I don’t know − I take everything one moment at a time and I count my blessings. But, right now, I’m happy and I’m just focusing on the music.”

The 36-year-old is to make her West End debut in the revival of stage hit Cats in December. She will take on the role of Grizabella in the Andrew Lloyd Webber production which will begin a limited run at the London Palladium.

Scherzinger said: “Andrew asked me to revive Cats. He is a great friend of mine and one of my mentors, and I’m so excited.

This is a great new chapter in my life. I’ve got a great new team behind me

“I love the theatre. It’s where the magic happens.This is a great new chapter in my life. I’ve got a great new team behind me, a new label and my album Big Fat Lie is finally coming out.”

The singer and model was a permanent member of The X Factor judging panel from 2012 but is not part of this year’s series as Cheryl Fernandez-Versini has returned. She insisted it was her decision to leave.

“It was definitely my choice not to come back,” she said. “I wanted to focus on my music and new album. But Simon didn’t call me to discuss it anyway.”

Last year’s show played an important role in helping her cope with turbulence in her relationship. She said: “If you’re ever going through hard times, if you just sit there... you end up going through this endless vicious cycle, and you cycle downwards. I saw the talent and beauty of my contestants and was like: ‘Come on let’s grow, let’s do this.’ Building them up essentially built me up and strengthened me.”

Scherzinger revealed she is still in touch with the 2012 winner James Arthur, who was dropped by Syco in June.

“He’s called me and been down about it, but he’s not giving up,” she said. “I won’t let him give up. James is a fighter and is ridiculously talented.

“The cream always rises to the top. We all make mistakes and everything happens for a reason. Sometimes we just gotta get checked. It’s called growing pains.”