Claire Trevett: High price paid for banal wrongdoing

So it is that National finds the full truth of the maxim that "wine and women bring misery".

Former minister Richard Worth resigned over rumours about women. Now Phil Heatley resigns over two bottles of wine. It was not a pretty sight.

When Mr Heatley walked in to announce he had resigned, his face was drawn. He sat down, flanked by National whip Chris Tremain and Simon Power, who entered Parliament in the same year as him and with whom he flatted in the early years. He drew a deep breath and went straight in.

"I have called this media conference today to announce my resignation ..."

It ended a week dominated by pillorying for his use of his ministerial credit card to buy wine and meals during the National Party conference, and for personal spending which he later reimbursed - a practice forbidden under the rules.

There were also banal details inviting ridicule - the $9.50 bill for Burger King, $15 at McDonald's, a dinner with Steven Joyce at Whangarei's Killer Prawn.

It was all worthy of some ribbing and a red face but not much more. There were apologies, tears and money was repaid.

The first hint journalists had that trouble was up yesterday was when news filtered through that the Prime Minister had cancelled his day in Christchurch and was flying back to Wellington. Soon after, Mr Heatley's office called a press conference.

The final straw was the two bottles of wine he bought on his credit card at 8:28pm on August 1 at a National Party conference. He had repaid it, but then the Prime Minister found they were described as "dinner" on the reconciliation form for his card that month. Mr Heatley signed that form.

The Prime Minister saw the form on Wednesday and called Mr Heatley in for an explanation that night.

Mr Heatley insisted it was an error but suggested he resign and requested that the Audit Office scan his accounts to ensure it was simply carelessness rather than systematic abuse. Mr Key suggested he simply stand aside and told Mr Heatley to sleep on it.

From Mr Heatley's face at the press conference yesterday morning it was doubtful much sleep was had at all.

He set out his reasons for resigning, his voice sometimes cracking. He said he had not lived up to his own standards and discovering he signed something that was wrong was too much.

Mr Key left the door open, but in his orgy of self-flagellation, Mr Heatley did not seem to want it.

"I think I need to spend a long time on the back benches."

Then Mr Heatley's press secretary put a hand on his shoulder to bring things to an end. Mr Heatley talked on even as he stood to leave, his face becoming more and more drawn.

The Prime Minister followed an hour later. He had accepted the resignation only with regret, he still had confidence in Mr Heatley.

He was asked if this meant any minister could now be felled by pure semantics - the wrong word, a careless signing and you're gone?

He said no, that he was aware ministers were human and would sometimes do silly things. But he did respect Mr Heatley for holding himself to such a high standard.