Paula Bennett says it was inevitable she'd leave the National Party, as soon as she'd been rolled as deputy leader.

The colourful former Deputy Prime Minister is bowing out after a 15-year career in politics.

She lost her deputy slot to Nicki Kaye, when Todd Muller rolled Simon Bridges as National's leader last month.

Paula Bennett told Mike Hosking it took her a couple of weeks to make the call.

"I thought, am I ever going to have the kind of success which I had. I always wanted to leave with some dignity, so maybe this was the right time.'

Paula Bennett isn’t the only person now having to look for new opportunities.

Comedian Tom Sainsbury - who made a name for himself impersonating Bennett, told Mike Hosking he was taken aback by her decision.

He says Paula Bennett was his favourite, but he's sure he'll be able to come up with someone else to take over.

LISTEN ABOVE AS TOM SAINSBURY AND PAULA BENNETT SPEAK TO MIKE HOSKING