The Prime Minister's chief of staff has offered to resign over the Government's handling of its contract to equip the ministerial vehicle fleet with new BMWs.
Thirty-four of the German luxury cars have been ordered to replace an existing fleet of three-year-old BMWs.
John Key admits his handling of the issue has been sloppy but denies claims by the Labour Party that he keeps changing his story.
He originally said that he was never asked to sign off on the contract and that the first he knew about it was when a Crown car driver told him the new vehicles were arriving.
He now acknowledges that he signed off on documents that mentioned the purchase but didn't read the papers.
Mr Key says he doesn't read every piece of paper that he signs, because that would be impossible.
Offer of resignation declined
He also says he did not know until late last week that his chief of staff, Wayne Eagleson, had met with the Department of Internal Affairs last July about the matter.
The department then ordered the cars in November.
He says Mr Eagleson has no recollection of the meeting and never advised him of it.
Mr Eagleson has apologised to the Prime Minister and offered to resign but Mr Key has declined the offer.