WASHINGTON (AP) _ Members of Congress don't often publicly acknowledge the degree to which lobbyists pull the legislative levers, but a frustrated Sen. Jake Garn told a room full of them, ''You ought to be ashamed.''

Thirteen years of work on the Senate Banking Committee with little to show for it provoked Garn, R-Utah, into offering an unusually unvarnished lesson in practical politics.

''Frankly ladies and gentlemen I'm getting sick of all of you ... and the whole game,'' he told lobbyists at a hearing Thursday. ''You ought to be ashamed along with the Congress. ... We don't do anything because everybody's looking out for their own bailiwick.''

The crowd in the committee room laughed nervously, but Garn wasn't smiling.

His five-minute lecture was sparked by the continued wrangling over legislation to give banks expanded powers. Garn, the senior Republican on the committee, and Sen. William Proxmire, D-Wis., the panel's chairman, are sponsoring narrowly crafted legislation that would permit banks to affiliate with securities firms under a parent holding company.

The bill more strictly separates the bank and securities affiliates than most bank lobbyists would prefer, and it does not address at all their desire to expand into insurance and real estate.

Sens. Alfonse M. D'Amato, R-N.Y., and Alan Cranston, D-Calif., have introduced rival legislation that would permit banks to affiliate with a wide range of business, including insurance, real estate, securities and manufacturing companies.

Although the D'Amato proposal gives banks more powers, Proxmire said it could have the anomalous effect of ruining banks' chances of getting any new powers.

Proxmire's bill pits bank lobbyists against the securities industry, with other interest groups sitting on the sidelines. But D'Amato's proposal could bring the securities industry a host of allies.

''If we open it up, you don't have to be very politically sensitive to recognize that it will kill the bill,'' Proxmire said. ''We're just taking on a real political juggernaut. So many insurance agents and so many real estate people will fight like tigers that you can forget about getting this next year or the year after.''

D'Amato, however, argued that now is the time to pass broad-based legislation. A congressional moratorium on piecemeal deregulation by federal agencies expires March 1.

''Why take the attitude that we will fail in an effort to comprehensively restructure the institutions. ... I think we have a splendid opportunity,'' he said.

Garn, in reply, said: ''My patience is growing very, very thin with the entire process. ... I'm at the point where I don't care what is done as long as we do something.''

He complained that a banking lobby distracted by internal squabbling has been unable to counter the efforts of securities, insurance and real estate lobbyists who fear losing business to banks.

''In 13 years, Chairman Proxmire and I have accumulated more than 20,000 pages of testimony on these issues and there still has been only one or two significant pieces of legislation passed in that time,'' he said. ''It's absurd. It's ridiculous.''

The reason, he said: ''Nobody really wants to give up their own self interest.''

''You've got the ... securities industry, the most concentrated industry in this country. ... Then you've got the ABA (American Bankers Association) that can't get their act together. ... Basically the SIA (Securities Industry Association) doesn't have to do very much while the bankers cut themselves up.

''Then you've got the insurance agents who don't give a damn about the whole thing as long as you protect their little bailiwick.''