London — The ancient gothic chamber has the air of a rich man's private club. Its scarlet benches and gold hangings are dimly lit by stained-glass windows. Gazing down from the walls are barons of the time of the Magna Carta. On a red sack stuffed with wool (from the days when overseas commonwealth trade revolved around wool) sits an elderly man who holds the oldest lay title in the country, the Lord Chancellor of England.
Speeches are filled with elaborate courtesies:
Speakers call each other ''my noble friend.'' Bishops can be ''right reverend prelates.'' Military men are called ''noble and gallant lords.'' When a vote is taken, the correct response is not a simple ''aye'' or ''no,'' but ''content'' or ''not content.''
The House of Lords, with its 1,183 members, is in fact the oldest legislative chamber in the world. It is controversial - but as two new developments are now indicating, it retains both vitality and a capacity to fascinate the British as one of the ultimate symbols of social class and standing here.
True, it is a nonelected anachronism - but it is also a reservoir of experience as well as a modest brake on the work of the more boisterous House of Commons. It can delay bills but not block them.
True, the Labour Party has long wanted to abolish it - but it is also a magnet for successful people, many of them Labour Party members, who want the reward and social cachet of a title and a coat of arms.
The two developments are:
* Although the Labour Party is committed to abolishing the House of Lords altogether, in the meantime it wants to boost its membership there. This is partly to influence legislation, but also as a way of rewarding a number of prominent members defeated in the Conservative electoral landslide June 9.
Under enormous party pressure, outgoing Labour leader Michael Foot has asked for more than 20 of his party faithful to be ennobled in the next honors list, which will come out soon to mark the dissolution of the previous parliament in May.
Prime Minister Margaret Thatcher replies privately, and her spokesmen reveal publicly, that this is far too many. One government source close to her says Labour can expect less than half the number it wants. In particular, Mrs. Thatcher objects to two former Labour whips being on the list. Titles, she says, should go only to former ministers or others of more than usual distinction.
* Sir Harold Wilson, whose six-year tenure as (Labour) prime minister was longer than anyone's since William Ewart Gladstone in the 19th century, always campaigned as a man of the people. He derided one of his Tory opponents, Lord Home, for being a peer.
But now that he has retired from the Commons, the same Sir Harold is said to be laying claim to an earldom, as former prime ministers have the traditional right to do.
This is a dilemma for Mrs. Thatcher. Since 1964 it has been the reformist policy of all governments to create only life peers, not hereditary ones.
An earldom is a hereditary title. It is true that Mrs. Thatcher has just broken with tradition by creating two hereditary titles (for Cabinet colleague William Whitelaw, and for the former speaker of the House of Commons, George Thomas.)
But, as pundits here were quick to point out, neither man has a male heir. So their new titles are in effect life peerages.
Sir Harold, however, has two sons. His title, if granted, would be the first genuine hereditary one since 1964 - and the Conservative Party would prefer Mrs. Thatcher to break precedent with a Tory, not a Labour man.
These issues may not seem momentous to outsiders. But they are the stuff of political gossip and social aspiration here. Next to the royal family, they provide a relief from the newspaper headlines of economic recession and factory closings.
''The House of Lords does have a definite role to play,'' says Lord Nicholas Bethell, one of the more active hereditary peers (and also a member of the European Parliament). But he also recognizes that many younger people see it as outdated: ''I'd be surprised,'' he says, ''if it lasts beyond the end of the century.''
In fact, the chamber is already seeing a measure of reform.
The number of life peerages has jumped from 43 in 1961 to 337 by 1983. Old hereditary peerages have been declining at the rate of about three a year since 1974 for lack of heirs.
At the very top there are still three ''peers of the blood royal'' - Prince Charles and the Dukes of Gloucester and Kent.
According to a House of Lords spokesman, 27 other dukes remain. But the dukedom of Leeds is now extinct, and neither Atholl nor Portland have heirs.
The number of marquises dropped by nine between 1961 and 1981. Two others have no heirs. Forty-six earldoms have gone and others are expected to follow by the end of this decade.
The House of Lords also plays a useful, if limited, parliamentary role. It can delay money bills by a month, and other bills by a year or less, but it retains considerable influence over governments, which often seek to avoid the political flap that a conflict with the Lords would generate.
Frequently, the House of Lords can get its own amendments adopted. It can also initiate bills, such as the one which made seatbelts in cars compulsory here.
Mrs. Thatcher and Mr. Foot are expected to reach a compromise on a lesser number of new Labour peers. As for Sir Harold, one suggestion is that he be made a life earl as well as a baron (synonymous with ''lord'') to enable him to be an active member of the Lords.
Meanwhile, being a member of the Lords is much less remunerative than being in the United States Congress. No member, be he duke, bishop (''lord spiritual'') or lord (''lord temporal''), receives any parliamentary salary whatever (though whips, chairmen of committees and some other officeholders earn up to $37,000 a year).
A mere lord may claim $:12 and 10 pence ($18.50) per ''sitting day,'' according to the Lords accounting office, and an additional $:11 (almost $17) per day for postage and secretarial help - hardly a princely sum.
For a lord who lives out of London and must spend the night here to attend sittings, reimbursement for housing is (STR)25 and 40 pence ($39) per night. ''Given London prices, about enough to qualify for a Salvation Army hostel,'' one peer comments.
An undercurrent of criticism of the Lords, much of it left-wing, continues.
The state opening of Parliament, held in the Lords chamber, was castigated by prominent Labourite Richard Crossman in 1967 as ''like the 'Prisoner of Zenda' but not nearly as smart or well done as it would be in Hollywood. . . . It's . . . far more comic, more untidy, more homely, less grand.''
The major recent reform was the creation of life peers in 1958. No suggestions since then, such as drastically reducing the number of hereditary peers, or flooding the house with 1,000 life peers who would vote for abolition - appear to be workable.
In its unique British way, the House of Lords remains, and is likely to remain, for quite some time to come.