'I am shocked': The AM Show hosts react to Todd Muller's resignation as National Party leader

The AM Show hosts have been left "shocked" after Todd Muller announced his resignation as the leader of the National Party on Tuesday morning.

Muller said the role had taken a heavy toll on him personally and after reflecting over the last several weeks "this has become untenable from a health perspective".

"For that reason I will be stepping down as leader effective immediately."

Muller had only been in the role for less than two months after rolling former leader Simon Bridges in May.

The news of his resignation broke on Tuesday morning with The AM Show host Duncan Garner calling the news "phenomenal".

"[It's] a massive devastating blow to the party."

Garner said he didn't think Muller and his deputy Nikki Kaye were ready to lead the National Party.

"From my understanding, from what I knew about this coup, Nikki Kaye and Todd Muller were in charge of getting the numbers for the leader [Simon Bridges] but that leader pulled out and didn't want the job at the end. He didn't have the guts for this and that's when Muller and Kaye were promoted and … they took it. 

"But they didn't look comfortable from day one. He didn't have a plan, that says everything. He was goldfishing from the start."

Sports presenter Mark Richardson said he was left "shocked" by the announcement but thought it was best for the party's interests.

"I say good on him for making this move, it would have been very, very easy to have gone 'I can't, people are relying on me so I need to see this through the election'. But it's not right for him, I think it's a great move."

Sacha McNeil agreed Muller wasn't "fronting up in so many situations".

The National Party will now be looking for a new leadership team for the upcoming September election.

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