Sharon Osbourne says spending time away from her children was her ''biggest mistake''.

The 61-year-old star and her husband Ozzy Osbourne both struggled to adjust to being parents because of their hectic lifestyles meaning they frequently traveled - and she said being away from their offspring is her ultimate regret.

Speaking on 'The Graham Norton Show', she admitted: ''We both worked to continue a lifestyle we had become accustomed to and we had to travel, so my kids spent quite a lot of time away from us and you can never get that time back.

''It was the biggest mistake I ever did. I don't know how but Jack and Kelly came out just great.''

Sharon's marriage to the Black Sabbath rocker was suffering after his addictions spiraled out of control, and she explained she had to ''walk away'' so they could reconcile.

She said: ''We are a team and the hardest thing I ever had to do was walk away.''

As well as their marital problems, their son Jack was diagnosed with multiple sclerosis last year and he recently insisted the tough times have helped the family grow and become ''even stronger''.

He previously explained: ''Years like this can either tear you apart or make you stronger - and with the Osbournes, it's made us even stronger.

''My illness has made us realize how fragile we all are and given us some perspective. When we're together, we are a tribe, it's business as usual - it's crazy.''