Essentially it comes down to this.
His Government has achieved fiscal stability against the tough background of the global financial crisis during which it took office in 2008, the huge government expenditure bills National inherited from its Labour predecessors, and the impact of the two major Christchurch earthquakes.
Key contends it comes down to running the country well ("in the end someone has to pay the bills - some want to print money, we want to earn it the old fashioned way"). That last jibe was obviously aimed at the Greens, who are odds on to be Labour's coalition partner if they get to form the next Government.
But, says Key, "if we can make a step change in New Zealand and in years to come when they eventually look back on this Government they will say of its legacy, 'I think that it held its nerve and fundamentally guided us through the global financial crisis and the Christchurch earthquakes and it set the country up to grow during a period of dramatic change in Asia and that is going to be a far bigger gift. New Zealanders will have jobs and families will have independence."'
The International Monetary Fund and ratings agency Standard & Poor's have both given New Zealand a good report card in the past fortnight.
But the question is whether good fundamentals will do the trick.
My contention is that with some very real fiscal gains now tucked under the Government's belt, it is time for Key - and English - to market internationally the fiscal stability that has been achieved against that tough background.
Right now things look relatively dire across the Tasman, where Treasurer Wayne Swan has unveiled a $20 billion budget deficit against a background where Australia has benefited from strong terms of trade in recent years - up 200 per cent compared with New Zealand's 120 per cent. The fact that English is now looking at posting a small budget surplus in 2014/15 is no mean feat and ought to be strongly plugged to Australian companies as a plus when it comes to siting operations here.
When Tony Abbott inherits the fiscal mismanagement that Julia Gillard and Swan have bequeathed the expected winner of the September elections, he will face a tough time bringing the Australian deficit under control.
Kiwis tend to be rather self-effacing when it comes to competing openly against Australia on anything other than the sports field. But there is now an opportunity to do just that in the business arena - to attract companies here with the jobs they bring. At the Vector Arena luncheon, there was an element of self-congratulation around the room that for once New Zealand does not have to tip its hat to Australia on the economic front.
There is also a chance (admittedly small) that the $75 million projected surplus will be higher, and, if the Treasury's growth projections turn out to be in the Cassandra category, that English will come close to posting a surplus next year.
This presents a conundrum for Key and English.
The Prime Minister says there'll be no big election-year lolly scramble. The Government is already giving an "effective tax cut" (his words, not mine) through the planned reductions in ACC levies which will stimulate consumption.
Holding the line will be difficult when opposition parties will be offering spend-ups.
Outside the cloistered confines of the business community, many people do not understand the necessity for New Zealand to stay competitive.
On the international stage, Key talks a reasonable game when it comes to promoting New Zealand's trade interests. But there is a chance for him to step up (S&P does after all rate New Zealand among the world's 10 less risky economies) and market what has been achieved on the fiscal front so that international investors have confidence to invest in our companies so they can grow.
This is already starting to happen.
But in my view Key could achieve a lot more for New Zealand - particularly as his former banking background gives him credibility in top investment circles - by taking an over-arching role in this area.
He could start by using his annual speech to the United Nations to do just that rather than rehearse arguments to win New Zealand a seat on the Security Council.
This would require Key to segue into an international statesman and jettison the ruddy salesmanship which he has used to spruik New Zealand on the Letterman show.
