Helen Mirren has admitted that her Prime Suspect role requires very little preparation.

During an appearance on ITV1's Parkinson, the award-winning actress explained that she couldn't feel more comfortable playing Detective Superintendent Jane Tennison and compared the role to trying on an old jacket.

"You know with Jane Tennison I don't do any preparation, I'm very lazy," she said. "I do a bit of learning of the lines before I walk on the set, but otherwise I don’t think about it.

"Because it's like putting on some old coat that you're so familiar with; you know where the sleeves are, you don't even think about it. Jane Tennison is a bit like that for me, one of those friends that you've never really liked but some how hang around in your life."

Parkinson airs at 10.20pm tonight on ITV1.