Less than 24 hours after National's Amy Adams announced she is stepping down from politics, TVNZ1 Breakfast host John Campbell struggled today to understand why the "enormously popular" MP would do so unless she had an issue with Simon Bridges' leadership.

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But Ms Adams, who lost to Mr Bridges last year in a bid to lead the party following Sir Bill English's retirement, denied a rift between the two.

During an interview with Ms Adams, the Breakfast host pointed out that Ms Adams remains a popular politician who could work in both urban and rural environments and was relatively liberal for the party.

"I just wonder, given how much you have to offer, why the hell are you leaving?" Campbell mused. "The reason which keeps popping in my head is that you don't see a particularly galvanised or exciting future under the current leadership."

However, Ms Adams said, while there will be speculation, she made the call based on herself and her future.

"I've always had a view of politics that there's perhaps two types - there are the career politicians and then there's the get in, give it everything and then go off and do something else brigade, and I've always seen myself in the latter campus," she said.

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When questioned if Mr Bridges was the "modern face of the National party" and the right person to lead National into the 2020 election, Ms Adams said he was "absolutely the right leader to take us into the election".

"He's had my 100 per cent support from the day that I lost in the leadership contest to him. He's been a mate all the way through that and I think he's a good leader.

"There is a range of views in National as there is in the country - I'm on the more socially liberal end of the spectrum, Simon is perhaps slightly on the more conservative side. New Zealand is that mix, the National Party's that mix, and one of the things I love about our party is that it embraces both sets of views."

Mr Bridges earlier told Breakfast it was sad to see Ms Adams, as well as MP Alastair Scott, leaving.

"If you look at them you can understand it," he said. "Politics does take the toll. I mean, in Amy's case she's got a family and life to get on with and she's achieved a lot in politics."

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Ms Adams told Breakfast the reality of politics was hard, and said more public understanding of the realities of the job would help.

"They perceive us as all fat and lazy and good-for-nothing and there for the wrong reasons," she said.

"It's a hard life, long hours, punishing schedule, no privacy, your family misses out, you're constantly in the public eye. You get to do amazing things and I love the job but it takes a toll.

"I've always thought that the day I've thought that the life was taking more out of me than I could give, then that was the time to step aside."

Campbell noted Ms Adams' elated demeanor on the show. She admitted it was a relief to shed the burden of keeping her departure a secret, after having made the decision several months ago.

"I've been incredibly privileged, loved it, but I don't want to hang around and take up space," she said. "Let someone else come in with some new energy and new ideas, and I think that's how you get a healthy democracy."

But, she said she's loved working on things "that make New Zealand better", including work on family and sexual violence, the work she did to create the expungement regime for historical homosexual offenses and getting better internet connectivity throughout the country.