Colin Craig's legal team have questioned Taxpayers' Union director Jordan Williams' real intention when he approached other members of the Conservative Party to "warn" them about their leader.
Williams is under cross examination at Craig's defamation trial in the High Court at Auckland, after giving evidence for two days this week.
Williams maintains he disclosed letters, poems and an alleged sex text Craig had sent his press secretary Rachel MacGregor, leading to her shock resignation before the 2014 general election, in a bid to protect her and the good reputation of the party.
He felt that Craig, who MacGregor alleged had sexually harassed her, was not the right person to lead a political party founded on Christian family values given what he saw as "inappropriate" behaviour towards the woman.
Williams is adamant he was, primarily, acting in MacGregor's best interest when he passed on material she had shown him in confidence.
However Craig's legal team have suggested his real intention was to have Craig removed from his position as party leader.
Revealed: Rachel MacGregor's personal messages to Colin Craig
Colin Craig defamation trial: Poems 'icing on the cake' after affair rumours
Colin Craig defamation trial: explosive sex harassment claims emerge
The court has heard much about a confidentiality agreement between MacGregor and Craig following the resolution of her sexual harassment complaint.
Williams said his friend was bound by that agreement so she could not disclose the information about Craig - but he felt it was crucial that the rest of the Conservative Party was aware.
Without MacGregor's permission, and despite her asking him specifically not to "use" the information "against Colin", Williams had a meeting with party members and told them what he knew.
Craig's lawyer Stephen Mills QC today challenged Williams on his intentions and ethics - suggesting his only intention in meeting Conservative Party members was to "remove" Craig as leader.
"The aim of this was to bring it to a head and bring closure - that closure was the removal of Mr Craig," Mills said.
Williams responded "yes", but reiterated his primary motivation was doing the right thing by his friend, even if that meant breaching her confidence, and possibly the confidentiality agreement.
"What was going through my head was 'is this the right thing to do?'" he said.
It was, and remains, his opinion that Craig "shouldn't be leading the party because of what happened with Rachel".
Williams said MacGregor's hands were tied by the agreement she had with Craig meaning she was silenced and could not speak publicly about her situation.
Meanwhile, he alleged, Craig repeatedly spoke about the resignation and MacGregor in media interviews.
This vexed Williams, driving him to go to party members effectively on her behalf.
The court heard Williams sought legal advice before passing on any information and would not have proceeded if his lawyers had told him not to.
The trial continues.
The case: Williams v Craig
Former Conservative Party leader Colin Craig is on trial in the High Court at Auckland for allegedly defaming Taxpayers' Union director Jordan Williams, a friend of Craig's former press secretary Rachel MacGregor, to whom she turned after her high-profile and sudden resignation shortly before the 2014 general election.
Williams said he was "horrified" at MacGregor's claims Craig had sexually harassed her, and after seeing letters and poems the politician sent her, revealed all to other Conservative Party members.
When Craig found out he publicly claimed Williams was part of a group of "culprits" determined to have him removed as party leader through a "campaign" of "false accusations".
At a press conference and in a pamphlet sent to more than 1.6 million households across the country that Williams was a liar and had "spread false accusations".
Williams then filed defamation proceedings in the High Court, saying he did not lie about Craig.
Set for five weeks before Justice Sarah Katz, this is the first civil defamation trial before a jury since 2002.