Key events in the election spending row 1999-2006
1999: Labour launches its pledge card, copying a British Labour Party election campaign strategy. Helen Clark leads her party to victory after nine years in opposition.
1999 post-election: The standard Parliamentary inquiry into the election raises concerns about campaign funding rules, broadcasting allocations and donation disclosure. It says the regime needs overhauling.
July 2002: Labour issues another pledge card in the election campaign that resulted in Labour's re-election and National recording its worst-ever level of political support. It was not widely known at the time, but Labour says now it used parliamentary funding for its pledge card in 2002 and 1999.
Post-July 2002: Concern over National's extensive use of its Parliamentary funding for campaign material, such as bill boards and pamphlets, sparks MPs to rewrite the rules. After the furore erupts in 2006, National says the rewrite shows Labour knowingly broke the rules in 2005. Labour says the changes were not relevant and it complied with the rules as it understood them.
August 2005: In the run up to the election Labour launches another pledge card.
It later emerges that it was warned by the then Chief Electoral Officer David Henry that it should be considered an election expense. This would have put Labour over the election cap.
September 2005: A number of complaints are made to the Electoral Commission about Labour and others over breaches of electoral law.
October 2005: Mr Henry refers numerous complaints to the police over breaches of election law concerning the nature of advertising and how it was funded.
December 2005: National admits it made a mistake over GST and has broken the broadcasting spending cap. It is also being investigated by the police for this.
10 February: Police investigate Labour Party for $440,000 spent on pledge cards and pamphlets during election campaign.
14 March: Crown Law receives police report on investigation into election overspending.
18 March: Police choose not to prosecute Labour for breaching electoral law, despite finding a prima facie case against it.
4 April: Auditor-General Kevin Brady announces he will investigate all election campaign spending.
20 May: Police papers reveal Labour Party offered to include the $446,000 spent on pledge cards in election expenses, but recanted after the election.
29 May: National proposes law change to allow election spending pay back after a misunderstanding between National and its advertising agency left the agency $112,000 out of pocket.
7 August: Solicitor-General states legal opinion that election spending may have been unlawful.
9 August: Winston Peters says Solicitor-General's "unlawful" views could be challenged in court.
11 August: National pays back more than $10,000 of taxpayer money spent during election campaign.
12 August: Labour proposes retrospective legislation to validate taxpayer-funded election spending that the Auditor-General finds unlawful.
14 August: PM Helen Clark announces no action will be taken over election overspending until Brady delivers his final report.
18 August: A legal letter from the Acting Solicitor-General contradicts Labour, New Zealand First and Act's claims they had approval for taxpayer-funded election spending.
22 August: Auditor-General Kevin Brady says he forewarned political parties last year to be careful with election spending, however Clark claims it is news to her.
1 September: Herald- DigiPoll finds 81 per cent of Labour supporters think the party should repay unlawfully spent money.
13 September: Labour strategist Pete Hodgson says his party will not repay any taxpayer money unlawfully spent on the election pledge card.
20 September: Brady accepts Green Party's spending of $20,000 on election campaign as legitimate.
21 September: Green Party joins parties pledging to pay back taxpayer money.
3 October: Parliament's Speaker Margaret Wilson delays proceedings in private legal challenge against Labour's pledge card until Auditor-General delivers report to Parliament.
12 October: Brady delivers final report on his inquiry into the election spending