He swears he can talk most of the audience round in that three minutes. His pitch is a mix of beating his little tomtom of patriotism and trying to dismantle his opponents' arguments. He wants something that "screams New Zealand". He points to the Canadian flag and Japan's rising sun as examples of memorable and distinct symbols on flags. He winds up with a warning - if this opportunity to change is wasted, it will be 50 years before it comes round again.
He does not think New Zealand will ever be like America but he would like to see a more "overt signs of patriotism". Key does not have a flag pole at his own home but when he first became Prime Minister, he had just two New Zealand flags behind him at his weekly press conference. He now has four.
Despite Key's enthusiasm, the response to the flag process appears to have been a big shrug of indifference. The roadshow meetings attracted average audiences of just 29 people. Many believe the $26 million budget could be better spent. Key's advocacy of it has led to it being dismissed as a "vanity project", an attempt to get himself a political legacy.
There are those who say the process is already dead in the water.
Labour Party leader Andrew Little, who supports change, says Key should cut his losses and mount a "strategic withdrawal" rather than let it go to the vote.
He doubts this will happen. Key has too much skin in the game. "He's certainly got a huge personal stake in it. He's made it his thing. And when you ask yourself what would drive it, I can't see anything outside his own personal desire to have a political legacy of his prime ministership."
Labour had pledged to go ahead with the referendum itself if it was in government after 2014. But it didn't take long to start criticising it. Labour's Trevor Mallard dismissed it as a "vanity project" for the Prime Minister. He took issue with the order the referendum questions were being asked, the cost, the "tasteless" timing, and the people selected for the panel - "a mixture of some wonderful people and a few National Party hacks".
Little denies Labour was trying to derail the process out of sour grapes. "This is not the time to be spending $26 million on a process to change the flag when there seems to be widespread indifference about it." He said the polls did not show any support for it and the turnout at public meetings was "pathetic". He was also wary that if the result of the referendum was strong opposition to change, it would put the topic out of bounds for another 10 to 20 years.
"So it may well be time for a strategic withdrawal."
Maori commentator Morgan Godfery says it may be true that Key wants a new flag as a legacy but criticises Labour for making it about Key instead of the flag, saying Key's motivations should not matter. "I think this is far bigger than the current Government, the next Government or the one after that. It's about the sort of country we want to be." Godfery worries it is now too late now to salvage the process, saying the perception it is a waste of money has set in. "I think it went off the track months ago not helped by the Labour Party making it explicitly political and rejecting the Government's attempt to put it beyond politics and give the country a legacy."
The Green Party has been less vocal in its criticism than Labour. Co-leader Metiria Turei said Key had missed the boat on public sentiment and doubted if he could drag it back up. "People will change the flag when they want to. He can't threaten New Zealanders by saying they will be stuck with it for 50 years."
Ironically, back in 2010 there was momentum for change but the Prime Minister ruled it out because of the global financial crisis. It was the first year the tino rangatiratanga flag was flown on Government buildings for Waitangi Day. The Herald was running a flag campaign, a number of well-known and respected New Zealanders were publicly in favour of change and there was more than 50 per cent support for change in a Herald-DigiPoll survey.
Key waited for four more years and after announcing a referendum in 2014, a Herald-Digipoll survey showed there was still more than 40 per cent support for change. But by Anzac Day 2015 that had dwindled to 25 per cent, partly driven by the Returned and Services Association's objections to a change and the centenary of the Anzac landings. Key is banking on support returning.
There are groups setting up on either side of the flag divide and preparing for battle. The two most visible pro-change groups so far are Gareth Morgan's Morgan Foundation and the NZ Flag group set up by the late Lloyd Morrison in 2003 and reincarnated by the Republican Movement's Lewis Holden. The RSA has taken the lead among those opposed to change with its Fight for our Flag campaign. Battles require war chests.
On Thursday, the RSA set up a fundraising drive on givealittle. RSA president BJ Clark hopes to keep the RSA campaign within $25,000. "We don't have the same finances as the proponents for change the flag." By this he doesn't mean a pro-change lobby group or even Gareth Morgan. He means the Government. Clark won't join those criticising Key for legacy or vanity projects.
"I'm disappointed that this has become a personal issue against the Prime Minister. He's entitled to make the decision, we don't agree with it and we will come out fighting but we won't play games of personalising it. He treats me with great respect and as the Prime Minister I will treat him with great respect as well."
The RSA is urging people to sabotage their first referendum ballot papers by spoiling them and writing that they vote for the current flag rather than ranking a shortlist of flag designs. The thinking is that a large "informal vote" count will register the level of protest. The timing of the Anzac centenary commemorations and low levels of support for change in polls gave the RSA a headstart, ensuring wall to wall media coverage.
Clark even says he has seen some attractive designs among the flags submitted. "Just 'cos it's attractive, doesn't mean to say it's the one. I find a large chocolate mousse very attractive, but it's going to have a disastrous result if I eat it."
Pro-change campaigner Gareth Morgan has the kind of money the RSA can only dream of. Morgan was overseas this week, but entered the pro-change campaign via his blog soon after the roadshow meetings began. He was galvanised by a poll that showed 88 per cent were against change and the news that only a handful of people had attended a roadshow meeting.
"These are just the sort of odds I revel in," he wrote. He dismissed the arguments against change as "a grab-bag of miscellanea with no single reason relevant to what is the most appropriate flag design".
Morgan launched his own design competition - with a prize of $20,000 and a billboard to display the winning flag, a flag he wanted to reflect the Treaty of Waitangi.
Also on the pro-change barricade is Lewis Holden at Change the Flag. He says it's too soon to call the process a failure, although he does think the public meetings were regrettable and should have been held at a different stage. His biggest push will be before the second referendum, promoting whichever design the public select. Holden is hoping the politics will disappear as people start to focus their minds on the final showdown between flags.
Godfery suspected there was more enthusiasm for change among Maori than the wider population.
"The current flag certainly doesn't represent Maori. If anything, it's quite antagonistic having the Union Jack anchored up there in the left corner. You could say the flag is a constant reminder of colonialism." He says that will not be a universally held view among Maori but marae tended to fly the United Tribes flag or Tino Rangitiratanga flag rather than the New Zealand flag. Unsurprisingly, the largest of the public meetings was at Waitangi at Te Tii Marae where 60 people turned up. It was at Waitangi that Maori chose the United Tribes flag as New Zealand's first official flag in 1834. Then there is the chasm of yawning indifference in the middle. In that space is Auckland advertising creative James Mok.
Mok has a Mike Davidson flag on his office wall, a stylised Union Jack that incorporates the koru. To him it embodies both the indigenous and colonial histories of New Zealand. "When people see it, they feel patriotism."
Despite that he does not believe the current process is worth it. He has no particular gripe with National or the Prime Minister, but says it is a waste of money, questioning the value of the referendum where there are no plans to look at broader constitutional change.
Key's tactic is to convert those who are ambivalent or likely to base their decision on the final design. That will depend on the new flag. About 10,000 flag designs were submitted to the panel of 12 notable New Zealanders who will select a shortlist of alternatives. A longlist of about 70 is expected next month and then the shortlist of four will be presented in September - allowing two months for the public to digest them before the postal referendum in November.
There are also several other websites getting into the design process. Designer Dan Newman entered some designs to the panel and set up the flagtest.nz website that allows people to roadtest their favourite flags on an animated flag pole in either a "raging southerly" or a mild nor'wester. He said that was to fill in one of the flaws of the official website, which didn't allow users to test flags.
Key does not believe apathy is as widespread as it seems, arguing that New Zealanders might not be going along to flag meetings on winter nights but they are talking about it in their own homes. But even he has admitted the bid may fall down due to "inertia." He believes interest will increase closer to the the referendum and people get an idea of how a new flag will look.
There are a lot of chances for three-minute speeches before then.
The next steps
August: Flag Consideration Panel releases longlist of about 70 flag designs for public input.
September: Shortlist of four flags is released.
November: First referendum to rank the shortlisted designs, a three-week postal vote.
March 2016: Second postal referendum between current flag and alternative.
