In 2006 Parkinson criticised Church's chat show debut

Church, 20, who is about to embark on the second series of her own chat show, said Parkinson had crossed the line.

"I said, "Mr Parkinson, are you serious?' He went, 'Oh, sorry, I shouldn't have asked that'," she told the Radio Times.

"Damn right he shouldn't, he's old enough to be my granddad," she added.

Last year Parkinson was critical of Church when she made her debut as a chat show host saying her producer should "have a word with her".

He said: "She need not swear so much, she need not remind us all the time that she's Welsh."

After the first series averaged ratings of 1.9 million viewers, Channel 4 commissioned two more runs of The Charlotte Church Show.

The former singer said she would refuse if producers wanted her to ask guests inappropriate questions.

"I'm not a sissy, but there's a line that you shouldn't cross," she says in the interview in this week's Radio Times.

"I know how uncomfortable it can be."