Key will suffer some momentary embarrassment at being found out in manufacturing a parliamentary equivalent of the "Big Lie" to deflect attention away from the Double Downgrade Day when Fitch Ratings and Standard & Poor's each knocked New Zealand's credit rating down a notch.
There may even be a parliamentary inquisition by the Privileges Committee if Labour succeeds with its breach of privilege complaint.
And while Key was somewhat shamefaced when challenged at his weekly press conference to respond to a Herald story which quoted S&P senior sovereign analyst Kyran Curry strongly refuting his claims, I doubt the PM will waste much sleep over it.
The reality is that Key's surreal antics have already deflected Labour.
If Goff had been seriously on form, he would have strongly rebounded by hammering home the fact that it was National which was (and still is) in Government at the time Standard & Poor's lowered New Zealand's sovereign rating on September 30 - some three weeks after the PM's snout sent his email. And some eight weeks before the election. Not after it.
He could have made great sport of turning Key's claim that S&P would lower the boom on NZ if Labour became Government by pointing out it had already crashed it down over Key's own head.
But instead of making light of the Prime Minister's nonsense, he has been drawn into side issues.
A diary conflict meant that I couldn't make this year's S&P event. But a quick roll call of the usual suspects suggests Curry was not dissembling in his comments to the Herald.
The invitation blurb had promised high-profile economists would analyse the opportunities and challenges facing both the global, regional and domestic economies, providing an insight into issues of real interest and concern to the financial markets.
Held at law firm Chapman Tripp's Auckland office on September 5, the event was moderated by Stephen Koukoulas, former economic advisor to Prime Minster Julia Gillard who is a market economist. Among the panellists were: John Bailey, who is managing director, Standard & Poor's Australia/New Zealand; S&P senior sovereign analyst Kyran Curry, BNZ chief economist Craig Ebert, ANZ market economist Khoon Goh, Westpac chief economist Dominick Stephens and ASB chief economist Nick Tuffley.
As Curry said: "I might have talked about the importance of the Government maintaining a strong fiscal position in the medium term but I would never have touched on individual parties."
As Standard & Poor's also said in its own pointed statement: "At no stage have we said that a rating downgrade was more likely if there were a change of government."
The real issue is the downgrade has happened for very good reasons.
The Government's hope that the Rugby World Cup would induce a short-term economic bonanza has yet to materialise. Though I am willing to wager New Zealand would indeed experience an economic confidence boost if the All Blacks do finally triumph. The expected boost from rebuilding quake-stricken Christchurch is not now going to happen in 2012 because major works can't begin until the ground stops shaking.
Finance Minister Bill English has drawn comfort from the fact that both S&P and Fitch Ratings have noted the Government has made some progress in getting its deficit and debt under control despite the global financial crisis and the Canterbury earthquakes.
But withdrawing the hefty "fiscal stimulus" that the Government applied in late 2008 and 2009 to avert a more damaging domestic recession will be very difficult.
Crown accounts for the year to June released yesterday showed a record $18.4 billion deficit in the 2010-2011 year - a blowout of $12 billion in just one year.
English announced the Government will triple the EQC levy to being replenishing the Earthquake Commission's funds.
The Finance Minister refused to get drawn into the Key/Goff stoush saying (rightly) that's just politics.
It's obvious that the press gallery will be alert to Key's diversionary tactics in future. He also needs to be very careful indeed to avoid being painted as the upbeat conductor furiously urging the orchestra on while the good ship New Zealand sails towards the rocks, instead of acting as the captain he should be.
But neither Key nor Goff can hide from the enormity of yesterday's figures.
Key might have wished that National's election hoardings - which he also unveiled yesterday - had contained more than empty slogans.
The first hoarding under the banner The Brighter Future Plan said "Balance the books sooner". The big question Prime Minister is how?
