National MP Simon Bridges has hit back at his demotion by leader Judith Collins last night, calling it "truly desperate". 

Bridges spoke outside Parliament less than 12 hours after his demotion over alleged comments to fellow National MP Jacqui Dean. 

Bridges said it showed she will go to any length to hold onto the leadership. 

He said there was a huge amount he wanted to say about what happened yesterday and how wrong it was and he would after talking to the caucus first. 

He had clear views about what he thought should happen to the National Party. He planned to hold a full press conference as soon as possible after that. Caucus was meeting at 9am. 

He sought a caucus meeting yesterday, but said Collins refused even though she was still at the precinct. 

She had finally agreed to having one this morning and he was looking forward to it. 

He will hold a fuller press conference after speaking to caucus. The Herald understands he has no intention of resigning. 

Collins announced Bridges' demotion in a release just after 9pm on Wednesday. 

The MP who laid the complaint against Simon Bridges is understood to be Jacqui Dean. It is understood to relate to crude comments Bridges allegedly made at a function about five years ago. 

Bridges is understood to have been talking with a group of about three fellow MPs, including Jami-Lee Ross and Todd McClay, when Dean walked past and the Tauranga MP called to her and made the comment. 

'National Party will not tolerate harassment and intimidation' 

In a written statement last night Collins said: "This evening, with unanimous support of the board of the National Party, Simon Bridges, Member for Tauranga, has been demoted and relieved of his portfolio responsibilities. 

"The decision follows an allegation of serious misconduct relating to Simon Bridges' interaction with a caucus colleague." 

It comes as speculation rises that Bridges was preparing to roll Collins as leader of the party. 

It is understood Bridges and the National MPs who back him tried to call a caucus meeting on Wednesday night but Collins blocked it. 

Some MPs are furious at Collins' move, saying it was a "ugly" and "f***ing ridiculous", and a clear bid to halt any leadership bid by Bridges by dredging up remarks from five years ago.