Key Points:

The Weekend Herald can reveal for the first time what Tau Henare said to provoke Cabinet minister Trevor Mallard to start a punch-up in a lobby off Parliament's debating chamber.

The three words that sent Mr Mallard into a rage on Wednesday were: "Shut up Sharon."

Although the name was wrong, the taunt about his private life was enough to provoke Mr Mallard into launching an attack which now threatens his front-bench position.

The minister, whose long-term marriage ended this year, said on Thursday that since the break-up he had become involved with former rowing champion Brenda Lawson.

He has apologised to Mr Henare and Prime Minister Helen Clark for resorting to violence, but faces a privilege complaint from Act leader Rodney Hide.

Mr Hide may strike problems in getting the Speaker to consider his complaint. Under Parliament's rules, a complaint of a breach of privilege has to be raised with the Speaker "at the earliest opportunity".

That means any complaint would have had to be received by the Speaker's office before Parliament met on Thursday afternoon. No complaints were received.

Mr Hide, who will write to the Speaker this weekend, said he became aware only on Thursday night that Mr Mallard had actually punched Mr Henare with a closed fist and was admitting it. He would argue that it was the timing of when he became aware that an MP had been punched by another MP that should determine the deadline for any complaint.

"It wouldn't look good if the Speaker refused to act on it."

Mr Hide said it made more sense for the privileges committee to deal with the incident, rather than the police having to deal with an assault claim made by a member of the public.

Asked why he was pursuing the matter when Mr Mallard had apologised and both MPs had been given stern tellings-off by their respective leaders, Mr Hide said Parliament needed to send a strong message "that you cannot go around thumping people".

"Parliament cannot turn a blind eye to a minister or an MP assaulting another MP."

The Weekend Herald yesterday put it to Mr Henare that he had been deliberately provocative. The MP, who on Thursday had said he accepted the apology and considered the matter closed, said he didn't think so.

"The funny thing about it all is that I'm the one who had the reputation for fisticuffs, even though I've never ever lost my rag and hit someone [in Parliament] and I'm quite pleased that I haven't. Is that enough to cause an international incident? I just think there are people who can dish it out but can't take it."

The inference was that although Mr Mallard was happy to goad former National Party leader Don Brash about his alleged affair with Business Roundtable vice-chairwoman Diane Foreman, he couldn't take the heat himself.

It's no secret that Mr Henare doesn't like the Labour heavyweight. It is said the tension goes back to Mr Mallard's treatment of Mr Henare's brother-in-law Tuku Morgan during the $89 underpants affair when both were New Zealand First MPs, but Mr Henare won't confirm that.

All he will say is that the animosity goes back to his time in the House from 1996-99 - the same time the Morgan controversy occurred.

"I like everyone in the House except for one person," Mr Henare said.

Who is that?

"Guess".

Asked yesterday whether Mr Mallard should face criminal charges over the stoush, Helen Clark said: "I think that is entirely a matter for the police. As is well known, governments do not direct police operations."

Asked if an apology from Mr Mallard was enough for her, Helen Clark said: "I will deal with Mr Mallard in my own way, in my own time."

The Prime Minister said she was "absolutely staggered" to hear Act leader Rodney Hide's comments on the matter.

"Rodney Hide, the very same person who was one of the members of Parliament who refused to vote to try to stop our young children getting thrashed."

Mr Henare reckons the bout between the two MPs distracts from the work he has undertaken during this last term.

He said that during his second "bite" at Parliament (he was re-elected in the 2005 elections), he had worked hard to dispel "myths" about who he was, caused in some part by the "staunch" Dirty Dog sunglasses he favoured during his first parliamentary stint from 1993 to 1999.

"The Dirty Dogs and the rough-and-tumble, that's bullshit."

Until now Mr Henare has kept his nose clean as a member of the Maori affairs committee and as his party's spokesman on Maori education and the Maori Development Ministry, and has worked hard on developing party policy in his areas of responsibility.

There have been no serious repercussions over the punch-up from party leader John Key, who has said that although the incident did not reflect well on anyone, Mr Mallard's transgression was worse for working his anger out through physical violence.

Said Mr Henare: "I don't feel bad about anything, absolutely not."