London — It is not often that the peers of the realm choose to act with urged resolution. Britain's House of Lords traditionally is regarded as a constitutional curiosity, a place where irrelevant aristocrats and political has-beens exist in exile from the party battle in the much more powerful House of Commons
But it has been demonstrated once again that there is life in the upper house and vigor in the ermine-clad men and women who inhabit it. By a decisive margin , the peers last week were able to rebuke the Prime Minister Margaret Thatcher and her government.
The issue may have been narrow -- a plan to stop paying for busing children to and from school. But the majority was crushing -- more than 100 votes -- and the Prime Minister was made to realize that when the peers feel strongly enough, they are a power in the land.
The House of Lords is far from being the political irrelevance it used to be. Introduction of nonhereditary life peerages in 1958 has seen to that.
Today, though the lords (and ladies) continue to foster the customs of yesteryear and seldom sully the air with the rough exchanges that routine in the Commons, upper chamber activities are very serious.
As well as people who owe their positions solely to the accident of birth, the lords now represent a wide range of professional skills. The modernized form of the lords, however, by no means renders it proof against criticism. Only a few weeks ago a bill was tabled in the House of Commons proposing that voting powers in the upper chamber be restricted to only 200 or so peers who, the sponsor believes, should offer themselves for election at regular intervals.
Even the Lord Chancellor, Lord Hailsham, who presides at House of Lords debates, favors change in the form of elections by proportional representation. Lord Hailsham considers that if the House of Lords does not reform itself and become more modern-looking, a future Labour government will decide to abolish it altogether.
But while debate about the futre shape of the lords continues, so, too, do its strangely outmoded ways.
In practice, debates are seldom attended by more than a hundred or two, and very often bills are considered by a chamber in which only a dozen or so peers are present.
It is on the big occasions that tradition is most apparent. When new peers are introduced, they must appear in the company of two sponsors. All wear full-length scarlet robes trimmed with fur, plus black cocked hats.
Accompanied by the Gentleman Usher of the Black Rod, the Carter King of Arms, the Earl Marshal, and the Lord Great Chamberlain, they approach the Lord Chancellor sitting on the woolsack. Kneeling, each new peer presents his writ of summons.
Then, having assumed their seats, the recruit and his sponsors rise and sit no less than three times while doffing their hats to the Lord Chancellor, who returns the compliment. Lord Hailsham has been observed scratching his full-bottomed wig vigorously with a ballpoint pen while the ceremony ensues.
Quirks such as this have provided critics of the House of Lords with ammunition. Most peers believe there will have to be significant changes in their institution before the end of the 1980s.
On the other hand, the crusted residue of the past does not prevent the House of Lords (and ladies) from acting decisively, as Mrs. Thatcher has learned.
Spurred on by Lord Butler, a former Conservative minister under Harold Macmillan, they opposed the government's provision on school busing on two grounds: that it was unfair to parents, and that it ran directly counter to the letter and spirit of the 1944 Education Act, a veritable pillar of British political and social reform.
When the lords voted, they were acting in a manner that the experience of centuries best fits them for: stopping an item of legislation that seems anathema to men of good sense who respect the institutions of established society.