The redrawing of parliamentary boundaries, effective this month, will mean 13 more members sitting in the House of Commons after the next election, bringing the total to 295. While the desks in the Commons are already rather too closely packed for comfort, it seems to me this does not go nearly far enough.

The most striking feature of the Canadian House is the banality of the backbench. Other parliamentary governments must always cast an uneasy glance over their shoulders each time they rise to speak. One thinks of the former British cabinet minister, Labour's Denis Healey, a stalwart NATO supporter, straining to make himself heard over the screams of: ''You bastard! '' from the Labour left. (Healey at last was provoked into shouting back: ''You f--ers! '' Asked about the exchange later, he smiled and said only, ''They questioned my paternity, so I praised their virility.'' Beats fuddle-duddle, doesn't it?)

No such vital dissent may be found in our own Parliament. The current edition is typical. The Tory dinosaurs content themselves making clownish and irrelevant fuss over hobbyhorse issues such as the metric system or bilingualism. But when a matter of real substance arises, on which a right-wing Tory might legitimately run amok, such as the grotesque $3.5-billion ransom paid to the five big oil companies in the Hibernia electoral extortion racket, they are silent.

Indeed, for all the reforms that were supposed to give greater independence to the individual MP, Canada's ferocious party discipline remains in most respects intact. Those few, solo MPs to break ranks have very quickly been isolated as confused and troubled souls - from broken homes don't you know, once dragged a dead dog into the Commons bar and called it Caesar, sad story really, don't spread it around. The bilingualism revolt, however quaint and misguided, was slapped down with appalling savagery.

The problem, I suggest, is one of numbers. The cabinet has grown so large that the chances of a backbencher reaching ministerial rank, even with the largest majority in the history of the country, are quite good: about one in five. Leave out those who have no desire for office, cross off the very unpopular or medically unfit, and the average reasonably intelligent, hard-working MP on the make can hardly avoid promotion within a term or two, if he keeps his nose clean. It is ambition, and the too-real chance of its fulfillment, that is the chief whip for the party line.

Since there is little prospect of the cabinet growing smaller, the most immediately beneficial reform would be to double or possibly triple the number of seats in the Commons. This would provide a large stock of MPs with no possible avenue of promotion, and hence nothing to keep them off the streets of political delinquency.

It would also increase the quotient of eccentrics and, with any luck, out-and-out madmen, to the furtherance of novel thought and creative mischief. With so much time on their hands, some might even be encouraged to do a little reading. Were our MPs so well-read, indeed so well-written, as so many British MPs seem to be, we might even aspire to the same quality of debate.

Needless to say, this would require some redesign of the interior. The Commons wardens advise that any further expansion, let alone an order of 600 new members, will mean ripping out the desks in front of each MP in favor of long, communal benches, as is the British style.

This in itself would be a major improvement. The Commons desks ceased to have any use once MPs abandoned the fine old Canadian tradition of desk- thumping for the insipid, pinkie-pointing gentility of hand-clapping as an expression of Some Hon. Members' approval (with the exception of Sheila Copps, who claps hands with a grim, deliberate vigor, as if she were bashing someone's face into a wall).

Behavioral research carried out in other forms of public housing have made clear the link between the surrounding environment and the attitudes of its inhabitants. Rows and rows of desks, beyond the obvious schoolroom imagery, encourage order, placeholding, regimentation. The desks themselves suggest an assembly of functionaries and paper-pushers, with exactly the tidy, soulless view of the world that could produce a Constitution with a section on sawlogs, poles and wood chips.

CONTEMPTUOUS SPRAWL

The stark unfurnished British model, on the other hand, the members simply sitting together like churchgoers in congregation, suggests a chamber of deliberation and debate, a council of elders, where affairs of state too grand and sweeping for sub-clause dissection are considered. It allows, moreover, for greater use of expressive poses as a silent intervention in debate - the reflective hunch, the contemptuous sprawl, the outraged leap to the feet - which generations of British legislators have perfected.

Of course it may be that, with between 600 and 900 MPs in the House, we will still be left short of room for everybody, as are the British. Churchill, it should be noted, very much favored this arrangement, believing it added the appropriate note of drama at times of urgent moment to see the members crowded in the aisles and round the Speaker's chair. Drama is not something we in Canada are drowning in.