KEY POINTS:
There is Classic Cullen. And there is the often classic Cullen. One was running around Addington under the watchful eye of the Prime Minister yesterday. The other was holding the fort back at Parliament in the Prime Minister's absence.
Neither had what you would call a classic sort of day.
Classic Cullen briefly led the field in the New Zealand Trotting Cup before fading and finishing well back.
Michael Cullen began badly in Parliament with a rare slip of the tongue before recovering to finish reasonably strongly.
Answering questions on Helen Clark's behalf, the politician was busy hosing down National's claim that Labour stands to benefit further from election-year restrictions on political advertising in the controversial Electoral Finance Bill because advertising by Government departments will be exempt.
National has discovered the Ministry of Health is planning to publicise Labour's primary health care strategy next year. Questioning Dr Cullen, National leader John Key cited this as an example of how such advertising can stray into the political.
Dr Cullen replied, "Any campaigning - sorry advertising - by Government departments ... " The rest of his answer - which emphasised such advertising has to be okayed first by the Auditor-General - was drowned out by National MPs rejoicing in a rare mistake by the Deputy Prime Minister.
However, Dr Cullen was quick to turn this error to his advantage. Unlike the Leader of the Opposition, he was not scared to go on Agenda, TVNZ's weekly politics programme, because he might let slip something he shouldn't.
Mr Key has twice declined invitations to go on Agenda, last week for family reasons and some weeks earlier for tactical reasons after National suffered a series of self-inflicted mishaps over state asset sales, raising doctors' fees and the party's stance on Iraq. However, Labour argues that it is unheard of for an Opposition leader to turn down such a platform.
Mr Key ignored Dr Cullen's taunt, instead sticking to his theme by questioning how the Prime Minister could have claimed election-year advertising by Government departments became "pretty sparse" as the election approached, when the $69 million spent on such advertising in 2005 had outstripped levels in previous and subsequent years.
Dr Cullen sought to explain this by noting that in 2005 there had been "new entitlements in some areas" - a reference to the income supplements and tax credits that came available under the Working for Families programme. Unlike National, Labour believed people should be made aware of things they were entitled to get.
But Mr Key was not finished with Dr Cullen, who coincidentally replaced him as the guest politician on last Sunday's Agenda.
In a separate question set down for the Prime Minister, he asked whether she had confidence in her Minister of Finance. "Better not make a slip this time," Dr Cullen joked, before not surprisingly confirming on Helen Clark's behalf that she indeed did have confidence in him.
Mr Key then brought up Dr Cullen's Agenda appearance, saying he had kneecapped the PM's efforts to persuade voters Labour is now committed to tax cuts by undercutting every argument in their favour.
Dr Cullen had already assured Parliament that he was "very enthusiastic" about delivering tax cuts. His Labour colleagues will have had fingers crossed that this was no slip of the tongue and that this version of Classic Cullen does not need the whip to talk up tax cuts.