ACT leader Rodney Hide is denying accusations he acted in a bullying and intimidating manner towards his former deputy Heather Roy.
At a caucus meeting on Tuesday, Mrs Roy was dumped in favour of John Boscawen. She subsequently resigned her three ministerial portfolios and is on two weeks' leave.
A document on her conflict with Mr Hide was leaked to the media on Wednesday.
As well out detailing the breakdown of the relationship, it contains e-mails in which Mrs Roy tells her leader she no longer feels safe meeting him alone and that Mr Hide had tried to undermine her as a minister on several occasions.
Mr Hide on Thursday rejected any allegations of bullying behaviour. He says there is no doubt he can be forceful, and remembers one meeting in particular where he was "quite strong" with Mrs Roy.
Mr Hide says that's the nature of politics. He admits being "strong" on some policy areas but says he is not a bully, and everyone who knows him knows that to be true.
The ACT leader also says claims that he raised Mrs Roy's performance with Defence Minister Wayne Mapp are untrue.
Mr Hide says Dr Mapp came to him with concerns about three separate defence papers prepared by Mrs Roy, who was his associate minister.
A spokesperson for Dr Mapp says Mrs Roy is no longer a minister and he has no comment to make.
Mr Hide has repeatedly refused to discuss his relationship with Mrs Roy, or any of the details relating to what happened at the meeting on Tuesday.
Mrs Roy, who has confirmed she intends to remain in Parliament as an ACT MP, says she is concerned the document has been made public, as it was a draft and not all of the material was presented to caucus.
Prime Minister John Key is standing by Mr Hide, saying he has been a reliable and effective government minister. He would not comment on any allegations of bullying behaviour.
However, Mr Key says the National Party will almost certainly run a candidate to contest Mr Hide's seat of Epsom in next year's election.
ACT rift damaging, says Douglas
ACT founder Sir Roger Douglas says the public spat between Mr Hide and Mrs Roy has damaged the party and its leader.
Sir Roger, the sole ACT MP to support Mrs Roy in the caucus, says the ACT brand has been damaged by the battle - which means Mr Hide and all the party has been damaged.
Though he has frequently expressed concern that the party needs to stick to its core values, Sir Roger believes ACT will get past this episode and says MPs are putting recent events behind them.
Sir Roger told Checkpoint on Thursday that what is in the past is in the past. He says he does not think Mr Hide and Mrs Roy necessarily agree on everything that transpires, but politicians have these sorts of disputes and can put it behind them.
Sir Roger says what is important now is to work on ACT's strategy and look to the 2011 election. He says he will see out this parliamentary term, but will decide next year whether to stand as an MP again.
Sir Roger was a Labour MP for 21 years, most notably as the Finance Minister during the Fourth Labour Government. He returned to Parliament in 2008 as a list MP for the ACT Party.
Former ACT MP Deborah Coddington says she doesn't believe the party will survive the battle.
Ms Coddington, who was in the party from 2002 to 2005, told Nine to Noon on Thursday the "disgraceful, tacky, unseemly fight" has gone too and it will further damage the party in the polls.