Rachel MacGregor has accused former Conservative Party leader Colin Craig of trying to frame her "as a mistress".
The former press secretary made the claim in a tweet sent out tonight.
"Colin Craig is trying to frame me as a mistress. There was never a sexual relationship, nor was there consent for his inappropriate actions."
The former Conservative Party press secretary has also accused Craig of breaking a confidentiality agreement and making inaccurate statements.
Ms MacGregor has not made any public comment since stepping down two days before the September election, apart from accusing Mr Craig of being "manipulative".
In a statement released by her lawyers this afternoon, she said Mr Craig had breached the agreement they signed after a Human Rights Commission mediation.
"Despite Mr Craig's public comments I have been advised by my lawyers that I am still bound by the confidentiality agreement," she said.
She was therefore unable to correct the "clear factual inaccuracies" made at Mr Craig's press conference this afternoon "without jeopardising my legal position".
Ms MacGregor said she was willing to correct those inaccuracies if Mr Craig agreed not to take legal action in relation to the confidentiality agreement.
"I am also willing to fully brief the Conservative Party board on Mr Craig's conduct, but, again this would require Mr Craig's consent," she said.
Mr Craig admitted at the press conference in Auckland that he might have breached the agreement, but said "wild and inaccurate" speculation meant he wanted to "set the record straight".
Colin Craig has admitted that some of his interactions with former press secretary Rachael MacGregor were "inappropriate", but rejects accusations of sexual harassment.
Mr Craig also said today that he had forgiven a $20,000 loan to Ms MacGregor, but that this was unrelated to her controversial resignation from the party immediately before the election.
Mr Craig made the comments at a press conference alongside his wife Helen Craig, who said she backed her husband.
In a statement, the Conservative Party founder said that he had not wanted to address allegations about his conduct with regard to Ms MacGregor.
But in the absence of information, media and others had been wrongly "filling in the gaps".
"In hindsight, on some occasions our conduct was inappropriate and we have acknowledged that so that we can both move on," he said.
"Let me make it very clear. I have never sexually harassed anyone and any allegations to the contrary are wrong."
Mr Craig described the allegations as "mischief-making" and expected media to "now set the record straight".
The former leader would not comment further, saying he was bound by a confidentiality agreement.
He conceded that some of the detail he had provided at the press conference might have breached the terms of the agreement.
Mr Craig refused to comment when asked whether he had inappropriately touched his former press secretary.
He would not be drawn on claims that a complaint had been laid with the Human Rights Commission. But he hinted at a dispute resolution, saying "that there was an issue we had to resolve".
A spokeswoman at the Human Rights Commission said she could not comment.
Mr Craig confirmed he had agreed to pay Ms MacGregor $16,000 for work she had done for the party, following her surprise resignation two days before the September election.
He also agreed to lend her $20,000 to cover outstanding credit card bills.
When Ms McGregor was unable to pay this money back, he and his wife agreed to forgive the loan.
Mr Craig said this payment had nothing to do with allegations of inappropriate conduct between him and his former press secretary.
"We received a request to forgive it on compassionate grounds," he said.
Ms MacGregor did not respond to a request for comment.
Mr Craig described his wife Helen, who has mostly been kept out of the spotlight, as "my biggest supporter".
In a brief statement, Mrs Craig said she did not speak to the media often but she had chosen to speak "in full and support" of her husband who she felt had been "falsely accused".
"I wanted to say how difficult the last few days have been with these wild and defamatory allegations being thrown around by the media," she said.
"Colin is a good man, and it has been distressing for me to see his character and reputation under constant attack."
Prime Minister John Key he did not know about the claims of sexual harassment and the allegations did not have an influence on National's pre-election decision to rule out the Conservatives as a potential coalition partner.
He was not concerned about the party's problems, saying National had not had to rely on the Conservatives for the past three election cycles.
The Conservative Party, which is morally conservative and campaigned on a platform of "family values", failed to win a seat in the September election.
It polled 3.97 per cent, below the 5 per cent threshold required for representation if no electorates seats were won.
- additional reporting Tess Nichol