National leader Don Brash has been forced to mount a desperate defence of his credibility just a week from the election, assuring the public: "I am not a liar".
It follows a u-turn yesterday over whether he knew about a $500,000 campaign against the Greens and Labour run by members of the Exclusive Brethren church.
Dr Brash first said he did not know who was behind the pamphlets, but yesterday admitted he knew the Brethren were planning to distribute such material, as they had informed him during a meeting within the past month.
Worsening the error was his apparent failure to appreciate the significance of both what he knew and his change of heart - which has exposed him to renewed accusations of naivete and misleading the public.
Dr Brash first conceded knowing the Brethren would circulate pamphlets in a radio interview yesterday, but failed to alert his senior MPs.
This put deputy leader Gerry Brownlee, the man sent out to deny National knew about the pamphlets, and strategist Murray McCully in extremely awkward situations.
Mr McCully was still maintaining National knew nothing about the pamphlets yesterday after Dr Brash's radio interview.
The first the pair knew about Dr Brash's changed tack was when reporters questioned the leader about the 95bFM interview after a party launch in Northcote to outline the first 10 things National would do.
Both men last night maintained they had no idea the Brethren had told Dr Brash of their plans.
Also undermining Dr Brash's attempts to retain credibility over the issue was his struggle to remember how often he had met the Exclusive Brethren over the past 18 months - which he yesterday estimated variously as two, three or four times.
He conceded he could not remember, also admitting on Close Up last night, "I've forgotten what city I was in", when referring to a press conference held the day before.
Dr Brash's decision to appear on Close Up just 90 minutes before the final TVNZ leaders' debate revealed just how rattled National insiders were yesterday - although they tried to play this down.
The National and Labour leaders had both cleared themselves of events to prepare for last night's final and hugely important debate.
Dr Brash would not have been advised to divert his attentionto such an interview unless itwas considered critical.
Senior Labour MP Pete Hodgson had accused Dr Brash of telling "an outright lie" and also accused Mr Brownlee of "deliberately misleading" the public.
"This kind of behaviour proves once and for all that National are simply not fit to govern."
Green co-leader Rod Donald also accused Dr Brash of lying.
On Tuesday, before it was revealed the Brethren were behind the campaign, Dr Brash continued to assert he did not know who was putting out the pamphlets.
The next day, after the Brethren connection was revealed, he refused to answer questions on the issue.
Last night Dr Brash angrily rejected the claims: " I can assure the New Zealand people I am not a liar".
He said he stood by all his comments and would not apologise.
While he had had "an idea" early on in the week the pamphlets might have come from the Brethren, he hadn't been sure, so it was not untrue to have said "I don't know where they came from".
In what appeared to be an attempt to divert the focus, Dr Brash then said the pamphlet he saw earlier in the week in Rotorua was an attack on the Greens, and as the Brethren had talked about an attack on the Government, he hadn't put the two things together.
He stressed National had not distributed or financed the pamphlets.
- additional reporting Kevin Taylor