Beware the ides of November, Don

An attempt within the National Party to topple leader Don Brash could be mounted next month.

The backers of National finance spokesman John Key have already taken soundings among caucus colleagues. It is understood they were taken four weeks ago but nothing came of them.

However, internal speculation is mounting of a stronger bid for the leadership being attempted by Mr Key next month or at the start of next year.

Mr Key did nothing last night to hose down the speculation, being less than emphatic at dismissing talk of a possible attempt in November.

"I have never had that raised with me," he said. "That is speculation I can't comment on and I don't know whether it is accurate or not but I don't anticipate that being the case.

"I'm supportive of the leader and I don't anticipate that position changing."

Asked if he would rule out contesting the leadership in the next six months, he said: "You're asking a hypothetical question and I just don't spend time on those because whatever answer I give can be misinterpreted for a number of reasons.

"I obviously can't predict the future. Anything is possible, obviously."

Asked again if he would rule it out if Dr Brash remained in good health and National's polls remained strong, he said: "I am not anticipating a challenge."

The soundings are said to have occurred in the same week that Dr Brash obtained caucus support to suspend maverick MP Brian Connell and the following week when Mr Key was at the Conservative Party conference in Britain.

He cancelled a visit the next week to the United States but said last night it was nothing to do with internal politics back home but because a holiday in Washington meant the trip would have been about three days.

Two weeks before that, news of Dr Brash's affair and confirmation that he was fighting to save his marriage led to speculation that his leadership had been weakened.

The soundings are said to have fizzled through lack of support - he would need at least 25 of the 48 MPs - and a lack of know-how in executing successful coups.

Mr Key said he did not know of any supporters who had been working the caucus for him. "I don't know what conversations people have with each other but I don't think that would be correct."

The MPs who spoke to the Herald would not say which of them took the soundings and on matters of leadership coups, but John Carter, Lockwood Smith, Wayne Mapp and Craig Foss are among those described as supportive of Mr Key.

An MP said last night the aim was to present a fait accompli to Dr Brash. But Mr Key did not quite have the numbers and there was too little control over too many possible outcomes to take it further.

That was a reference to the fact that while Mr Key has clear leadership ambitions, so too has former leader Bill English, as well as there being four possibilities for deputies in various scenarios: Gerry Brownlee, Simon Power, Katherine Rich and Judith Collins. "It was tactical retreat," another MP said last night. "It's not going away. Timing is everything."

That MP thought the best time would be soon after New Year in order that momentum to change could be maintained. Another thought the best time was as soon as possible.

A TVNZ poll shows Mr Key's popularity as preferred Prime Minister is growing.