Toward the end of his speech in the Commons Tuesday, Michael Wilson began to take on ominously Churchillian tones: ''Let it not be said that we lost the battle by abandoning it before it was won . . . We must not fail in our resolve.'' It was all very inspiring, and I confess I dabbed a tear.

But Winston Churchill was never much of a Finance minister either. In his sixth budget, Wilson has once again failed to back his rhetoric with resolution; with the kind of action on spending that would offer some evidence of understanding of the fiscal straits we are in. It's as if, having vowed to fight on the beaches and fight in the hills, Churchill had skipped to St. Tropez for the weekend.

Most of the early criticism has been diverted down a couple of side alleys. Bay Street economists seem unanimous in dismissing the budget's assumptions on inflation, economic growth and particularly interest rates as overly optimistic. Perhaps they are, but as far as interest rates go, one prediction is of about as much use as another.

Meanwhile, opposition critics and provincial finance ministers are howling that Wilson has simply passed the federal government's difficulties to the provinces, through restraints on transfers. ''He's forcing the provinces to impose higher taxes on Canadians,'' said Opposition Leader Herb Gray. No, he's not. He's forcing them to choose: control spending in other areas, borrow more or raise taxes. Maybe that's unfair but it does not, as seems to be the universal assumption, automatically mean higher taxes.

NO SQUEEZE ON SPENDING

In any case, the real point is that, even with optimistic assumptions and the squeeze on the provinces, the budget makes no headway on spending. This isn't just interest payments. Program expenditures are up 3% this year, 4% next, and 5% the year after that.

The problem, in general, seems to be that we lack a proper yardstick against which to measure spending. If we are ever to clean up this mess, we need some protocols on what constitutes an acceptable record on spending, and on whether spending is rising or falling.

The government seems genuinely aggrieved that critics have not given it more recognition for its achievements to date in keeping program spending to an average 3.5%-a-year increase. And in normal times, they might well be in line for mild congratulations. But these are not normal times. With a national debt of $351 billion and interest rates in double digits, an adequate performance is simply inadequate.

Things are so far gone that a temporary freeze, or even the 5% increases in spending planned in most areas, are classed as ''cuts,'' because they are less than the government had earlier thought it might like to spend. By the same logic, the deficit of $28.5 billion now projected for fiscal 1991 should be called an increase of $500 million from the government's previous forecast.

But so fully have the press swallowed the government's line that this is instead most often reported as a $2-billion decrease - from the current year's deficit. Spending is reckoned against future projections, or past performance, strictly according to which is most flattering to the government.

Even on the government's definition, expenditure savings amount to $2.8 billion, out of a budget of $147.5 billion. This was reckoned to be the most that could realistically be expected. Understand the implication: the programs Ottawa funds are all so essential, their delivery so lean, Wilson could find only 2% butterfat. The federal government is 98% efficient.

So it is taken as a remarkable sacrifice that, for example, the Canada Mortgage & Housing Corp. will only increase spending by $90 million this year, instead of $106 million - a saving of $16 million, from a budget of $1.7 billion. Grants to business have allegedly been terminated. But the Atlantic Canada Opportunities Agency ($370 million) the Western Diversification Fund ($287 million) and the Export Development Corp. ($185 million) all keep their allocations. And, needless to say, the $5 billion or so in handouts to the agriculture industry - whoops, ''farmers'' - is untouched.

The financial markets are unlikely to be appeased by this, especially after they get a look at the provincial budgets in the spring. When this, the budget to end all budgets, the this-time-we-really-mean-it budget, is seen for the failure that it is, they will descend in all their fury, leaving the Finance minister's projections strewn about like matchsticks. Look for another mini-budget, perhaps in June. Then roll on the International Monetary Fund.