The MP at the centre of last night's allegation of serious misconduct against Tauranga MP Simon Bridges, which ultimately led to the demise of National leader Judith Collins today, has spoken out.

Jacqui Dean, the MP for Waitaki, says in a statement that comments made by Bridges five years ago have resurfaced in her mind recently but that Bridges has 'reiterated his apology”.

'About five years ago, Simon Bridges made remarks that upset me at the time,” says Dean.

'They were not about me, but they were inappropriate and not something I wanted to hear.

'At the time there was an apology, but subsequently it has continued to play on my mind and with the recent reviews that have occurred in Parliament the feelings have been brought back up.

'What matters to me is that all of us have a clear understanding of what behaviour we should expect in a modern workplace environment.

'Simon and I have spoken a number of times over the past few hours and he has reiterated his apology.”

In a statement last night, Collins announced that Bridges had been demoted and relieved of his portfolio responsibilities due to the allegation.

However, after a caucus meeting this morning, Collins was issued with a motion of no confidence, says new interim leader Dr Shane Reti.

He says the caucus was "concerned" with the content of the media release issued by Collins last night and the process.

That motion was successful and Collins confirmed she was no longer leader of the National party on her Twitter account.

Dean is now hoping for privacy regarding the incident.

'As I'm sure can be appreciated, the publicity around this has been upsetting and I ask that my privacy is respected on this,” she says.

• Additional reporting RNZ