IN last week's column, I wrote that the coalition government's key political success since taking office was to have pinned the blame for the savage spending cuts it is implementing on Labour.
It is no small matter. On the question of who takes the rap for the country's current economic plight will hang much of the politics of the next five years.
If the government can hold the line all the way to the next election, it is inconceivable that the electorate would let Labour back in after just one term in opposition to atone for its economic sins.
But this, in turn, depends utterly on how the economy actually performs – and whether Chancellor George Osborne is proved right in his strategy of putting deficit reduction before economic growth.
Up until now, the country has by and large been prepared to give Mr Osborne the benefit of the doubt on this point.
Whenever Labour politicians – notably Ed Balls –have tried to argue the opposing point of view, they have been swiftly condemned as "deficit deniers."
But this week came the first sign of a chink in the Coalition's economic armour – a 0.5pc fall in GDP during the final quarter of 2010, following two preceding quarters in which the economy grew.
Could it be that Mr Balls was right after all, and that far from providing a springboard for recovery, the Coalition's deficit reduction strategy is actually strangling it?
Timing is everything in politics and in one respect, the GDP figures could not have come at a better time for Mr Balls, newly-installed as Shadow Chancellor following Alan Johnson's surprise resignation last week.
He certainly made the most of the opportunity, tearing into Mr Osborne with a self-assuredness that made the Chancellor look like the new kid on the block.
"My message to George Osborne is – get a Plan B, get a policy for jobs and growth and do it quick," he said, winning the war of the soundbites with some ease.
Mr Osborne's cause was not helped by the fact that he tried to blame the fall in output on the weather, which, as one union leader put it, sounded "a bit like a rail boss blaming delays on leaves on the line."
Whether this week's exchanges will turn out to be of lasting significance will of course depend on where the economy goes from here.
The risk factors for the government are obvious. This month’s VAT rise seems hardly likely to encourage a resumption in the growth trend, while there remains the risk of another cold snap.
Some observers have argued that having clamped down on spending in last year’s comprehensive spending review, Mr Osborne would use his March Budget to shift to a more pro-growth strategy.
Had this week's figures turned out positive, he could have done that from a position of strength - but to do so now would look more like a panic-induced U-turn.
Either way, if the next set of figures in April show the growth trend resuming, Mr Osborne will be off the hook and Mr Balls and Labour will be back at square one.
But if on the other hand they show another fall, then the UK will officially be back in recession and the dreaded "double-dip" will have become a reality.
Not only would that give Mr Balls the whip-hand in the economic debate, it would start to shatter the current consensus that the cuts are (a) necessary, and (b) Labour’s fault.
And the voters might then start to conclude that not only did we have the wrong kind of snow last month, but that we also have the wrong kind of government.