Clubs such as White's, whose members include David Cameron, the Tory party leader, will be forced to accept female members.
A review by the Department for Trade and Industry designed to plug the gaps in existing equality laws, is examining ways of banning single-sex drinking and dining clubs. The revamp would also include working men's clubs.
But the move is likely to provoke grumblings over the brandies if the Government wipes out centuries of tradition. And it will infuriate Tory MPs who accuse the Government of unnecessary interference.
Nicholas Soames, Tory MP for Mid Sussex and a member of both White's and Pratt's, said: "I would have thought they have got better things to do. It is a load of nonsense."
The end of men-only dens is being welcomed by many. The broadcaster Jennie Bond said: "It's about bloody time. Having clubs where membership is barred to half the population is absurd, ridiculous and antediluvian. It's pompous, astonishing and horrible. It really gets my hackles up."
Amanda Platell, the commentator and a former aide to William Hague, said: "I'd like to see their doors open to women but I wouldn't want to be one of the women walking in."
A catch-all equality Bill, to be introduced before the next election, will streamline equality laws and force single-sex clubs to justify their exemption. It will also extend fresh protection from discrimination to groups not covered by current discrimination laws.
These include transsexuals, who will gain fresh protection and whom hotel owners will no longer be able to deny a room. Shops and other companies providing "goods and services" would also be covered, giving transsexuals the same protection as homosexuals.
Only those single-sex clubs where gender is integral to the purpose of their existence, such as women's gyms or male gender support groups such as Fathers 4 Justice, will be allowed to retain their exclusivity.
"The issue of single-sex clubs is very much something that is in the mix for the equality bill. Men-only clubs are something that is being looked at. There are different ways we could do it and that is what they are looking at," said a senior Whitehall source.
The single equality Bill will consolidate 20 to 30 items of legislation outlawing discrimination on the basis of age, race, sex, disability, religion and sexual orientation.
One minister said: "The equality Bill is examining private clubs. Our view is that it is hard to justify their existence. There is the issue of what happens if you are a woman and if your local drinking establishment is a men-only club."
However, the move to end the male-only institution is not welcomed by all women. Novelist Jilly Cooper said: "If a lot of men want to have fun together, then why the hell can't they? Poor things. Why should men have to admit women?
"Should Eton have to have girls? Everyone has the right to congregate together. I don't see why anybody should admit anybody they don't want to."
Doorstepping: Waiter! There's a woman here!
As London clubs go, there is none quite so exclusive and relentlessly all-male as White's. Reporter Danielle Gusmaroli went along to try to penetrate this closed world
Who for? Traditionally for higher ranks of the aristocracy and upper echelons. Women not allowed.
Famous member: Tory leader David Cameron.
Gatecrasher's report: At first, no one around. Just as I venture deeper into the foyer, I am stopped by a porter who appears, as if by magic, wearing tails and shiny shoes. "Madam!" he screeches. "Women are not allowed in." "Don't be so ridiculous," I say. "I am here to meet someone." "Who?" he demands. "Lord..." He grabs his handbook, flicks nervously through the pages and defiantly declares: "He is not a member. I'm afraid you must leave." Oh well.Reuse content