JUST IN TIME for Christmas, it seems we have a real-life, modern-day Scrooge. But he's not like the mean-spirited, quivering old codger in Charles Dickens' "A Christmas Carol," sputtering and ugly and wondering how in blazes his silly nephew could be merry because he was "poor enough." Nor does the visage of today's Scrooge resemble that ornery old fictional curmudgeon that, every year about this time, flickers across our TV screens.

No, quite the contrary. This Scrooge is handsome, youthful looking beyond his years. On top of that, he is smooth and honey-tongued. In fact, many of the cliches apply: while butter probably does not melt in his mouth, his smile is warm enough to melt the heart of his fellow citizens, even when his actions and decisions threaten to rob them of their future.

This is a Scrooge in lamb's clothing, a man who is so affable, so homey, so good-natured that it is darn near impossible to dislike him. Indeed, it seems he is so loved by his charges that they keep on liking him even as he goes about trimming back on the amount of food and education they get. They believe him when he says that fattening the defense budget is for their own good because it protects them from the nasty Communists -- his version of a Grinch, no doubt.

It is only when this sweet-talking Scrooge starts slinging his budget-cutting ax like some Paul Bunyan that the ugliness of the situation starts to show. And what shows is not just the ugliness of Scrooge 1981. Because when budgets get trimmed, it is only the poor who end up screaming. Nobody else seems to hear them or, if they do, much care. Most are too busy worrying about their own financial future. They can't see beyond their own shrinking dollar. They just keep hoping things will get better. After all, that's what lovable old Scrooge promises will happen if they just let him do what he thinks is best.

Besides, he had assured Americans that certain things would be spared the ax. Programs such as Head Start for preschool children from low-income homes, he pledged, would be forever safe from budget trims. Head Start was one of seven essential programs, we were told not too long ago. It had done a good job. And it was still desperately needed.

For those of us who had been worrying about the future of our nation's poor children and who had been driven to near distraction by all of the other health and welfare program cuts, that was good news. Here was a program that had proven successes. Underprivileged kids who had participated in the preschool Head Start Program have been shown to do better in school than those who had not had the advantage of Head Start. In fact, what was really needed was more Head Start because only 20 percent of the American children who need it can participate.

At least Head Start was safe, we sighed with relief. At least some lucky kids would have a chance at an equal start in life.

But lo and behold, just in time for Christmas, Scrooge has reminded us he is still a skinflint at heart. Merry Christmas, poor preschoolers: the 374,000 of you in Head Start programs across the country may be among the last because Scrooge's helpers have proposed phasing out Head Start by merging it into community service block grants over the next four years.

Now, everybody knows that that is just a way of saying the program's days are numbered. Consider this: in the meantime, Scrooge's helpers are recommending that, starting in 1983, Head Start's budget be cut to $780 million from the $912 million Congress has okayed for 1982.

Typical is the reaction of Marian Wright Edelman, president of the Children's Defense Fund. "This is outrageous," she said. "This is the most successful program . . . They are out to gut the very nature of the program."

Of course, we all know that Dickens' tale has a happy ending. Scrooge eventually has a dramatic change of heart, thanks to an evening's encounter with Christmases Past, Present and Future, and showers everyone in sight with gifts and joy. But I have serious doubt that our real-life Scrooge will ever undergo such a dramatic metamorphosis.

Not as long as he believes eradicating budget deficits is more important than educating the poor.