New Zealand First leader Winston Peters says bringing up the marital status of Jami-Lee Ross is a "vicious" tactic that shows the National Party has no substantive defence against Ross' bombshell allegations.

Ross told reporters yesterday he was marched into National leader Simon Bridges' office about three weeks ago and told of four independent accusations of harassment from women.

He said he was to be stripped of his portfolios and dumped on the backbenches, and when he tried to find out more information about the allegations, Bridges threatened him.

"I asked for details. I was not given any ... He told me if I kept asking for natural justice, that it would not be just four women. It would be 15 women."

Last night, National deputy leader Paula Bennett said the leadership team raised issues with Ross - but it wasn't about harassment.

"At no point was the matter of sexual harassment ever put to Jami-Lee Ross," Bennett told the Herald.

"What was put to him was inappropriate behaviour that is unacceptable from a married Member of Parliament."

This afternoon, Peters said the mention of Ross' marital status was not "a sound strategy on her part".

"I thought an MP making those sorts of statements is on seriously dangerous ground.

"It was underhanded, vicious, uncalled for. When you see those sorts of tactics, it means you're bereft of any defence, and now you're playing for sheer hurt."

New Zealand First MP Shane Jones agreed.

"Marriage discussions in politics are a quagmire, and the notion that Paula, of all people, should be offering marital advice is dangerous territory."

Asked to explain what that meant, Jones added: "Leave those matters in the province of personal influence. Don't bring them into the world of professional politics."

Peters said it was clear that Ross, who says he has a taped phone conversation with Bridges and is laying a formal complaint with police about alleged electoral donation fraud, was getting sound legal advice.

"He has already quoted, to my knowledge, two statements from that tape. If that tape stands up, then the National Party is in serious trouble."

Bridges and the National Party have invited any police probe, confident they would be cleared of any wrongdoing.