Lone Ranger Tamihere betrays his faithful Tonto

Waimakariri MP Clayton Cosgrove first made his name as former Labour leader Mike Moore's lieutenant, but he is now best known as John Tamihere's trusty sidekick.

When Mr Tamihere lashed out at TV3's Duncan Garner and Act leader Rodney Hide in the House after being cleared by the Serious Fraud Office, Mr Cosgrove acted as his parliamentary chorus.

Last year, before Mr Tamihere agreed to stand down from the Cabinet while the SFO investigated, Mr Cosgrove spent days in Auckland at his distressed friend's side.

That all changed on Sunday when Investigate editor Ian Wishart released the last of the damaging comments by Mr Tamihere.

Mr Cosgrove was "getting nowhere" in the Clark Administration, Mr Tamihere alleged, because of his role supporting Mr Moore during the bitter 1993 leadership coup won by Helen Clark.

"What he used to do is get Clark's home number and [husband] Peter Davis' work number and home number and ... he used to drive them nuts, he'd ring incessantly at all hours, saying, 'Leave Mike alone,' and they knew it was him. He ran that campaign and it used to be nasty, naughty."

Mr Cosgrove labelled the comments "fantasy".

He said yesterday: "I know of no such phone calls, I made none, I'm a professional and I would not engage in that sort of grubby activity. I'm numbed by it, I'm baffled by it and I have no answers."

Helen Clark yesterday backed Mr Cosgrove, who now chairs Parliament's important finance and expenditure committee.

"I do not believe he made such phone calls to me and I'd be extremely surprised if he made them to anybody else," the Prime Minister said.

NZ First MP Ron Mark, who has contested the Waimakariri seat against Mr Cosgrove twice, questions the attempts to paint this Tamihere talk as deluded.

"It's my understanding that Clayton was intimately involved in running the defensive and offensive for Mike."

Whatever the extent of Mr Cosgrove's former involvement in the cut-throat world of party politics, he is certainly used by the present Administration as one of its hard-hitters.

When Labour decided to compare National leader Don Brash's race politics to those of Australia's Pauline Hanson, it gave Mr Cosgrove the job, and he is frequently sent after Mr Hide.

While Mr Tamihere may have caused Helen Clark and Mr Cosgrove some temporary embarrassment, he may also have given the latter the excuse he needed to cut himself loose from his former great mate.

Clayton Cosgrove

* Age 35.

* Labour Party member since he was 14. MP since 1999.

* Former public affairs manager for Clear Communications.