Shock in political circles at the sudden fall of Simon Bridges. 

National party leader Judith Collins has demoted the MP and relieved him of his portfolios, after a serious complaint made by a female caucus colleague. 

She says the seriousness of the situation demands a swift and decisive response. 

The MP at the centre of the case is understood to be Waitaki MP Jacqui Dean. 

Newstalk ZB Chief Political Reporter Jason Walls says told Kate Hawkesby it was something even people within the party weren't expecting. 

“Genuinely couldn’t believe it. It was shock on a Jami-Lee Ross level. It was shocking.” 

 Judith Collins, Shane Reti and Jacqui Dean are expected to front a press conference at 10am. 

LISTEN ABOVE