'I didn't know that I was on trial for my decisions as a minister' - Nick Smith testifies in court over poison protest

National MP Nick Smith has described to a Nelson court how a protest against him allegedly involving poison was the first time he'd felt "physically threatened" at his regular spot at the local market.

Nelson woman Rose Renton is facing a charge of offensive behaviour following a protest against Dr Smith in September last year. She denies the charge.

The former Environment Minister was today called to the witness stand to testify in a Justice of the Peace hearing, describing the incident as "most serious".

On September 2nd, 2017, the MP was at Nelson's Saturday market in Montgomery Square when Renton approached him over a brodifacoum poison drop that was underway at Brook Waimarama Sanctuary, five kilometres away.

Cellphone footage played to the court shows Renton and another man confronting the politician with rat poison.

However, Dr Smith told the court the videos only told part of the story and "had not captured what was thrown" at him.

Renton has denied Dr Smith's claims she "rubbed poison" onto his body.

In a recording of a police interview played to the court, Renton revealed that she had bought rat bait from The Warehouse earlier that day, motivated by an "emotional" scene she had witnessed outside the Brook Sanctuary.

She said she had suggested to her husband at the time that "it would be a good idea to show Nick Smith what it felt like to be violated".

"For me it was a simple message. To show what it's like to have poison up close and personal," she told the officer in charge.

Under cross examination, Dr Smith objected to defence lawyer Sue Grey's line of questioning.

Ms Grey said she wanted to establish the circumstances around Renton's protest. She pointed to the former minister's influence over changes to the Resource Management Act in 2017, which enabled the aerial poison drop in Nelson to go ahead.

Dr Smith told Ms Grey she was turning the court case "into a political debate".

"I didn't know that I was on trial for my decisions as a minister," Dr Smith said.

The hearing continues.

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