The Senate ethics committee, which is considering a proposed censure of Sen. Dave Durenberger (R-Minn.), is facing a series of far more complex and politically contentious ethics cases later this summer, including allegations that helped set off the growing political storm over the cost of the savings and loan industry collapse.

On the surface, the cases are similar: Durenberger, like five of his colleagues who have been accused of improperly intervening on behalf of savings and loan entrepreneur Charles H. Keating Jr., is charged with violating Senate rules aimed at assuring the ethical conduct of lawmakers.

But the similarity ends at the surface. While Durenberger was charged with violating specific rules and did not contest most facts in his case, the rules are fuzzy and the facts are disputed in the cases of the so-called "Keating Five" and a sixth senator, Alfonse M. D'Amato (R-N.Y.), who is accused of improperly pressuring federal agencies to help relatives and supporters.

So the committee's apparently tough approach to Durenberger does not necessarily offer any clues to the outcome of the other cases, which are likely to reach critical points this summer, probably around the time the Senate renders a final verdict in Durenberger's case.

Consideration of the Keating-related cases is further complicated by the mounting political furor over the soaring costs of the savings and loan industry cleanup as was underscored last week by the angry debate between the White House and congressional Democrats over who was most responsible for the debacle.

Four of the "Keating Five" are Democrats, including Majority Whip Alan Cranston (D-Calif.) and Banking Committee Chairman Donald W. Riegle Jr. (D-Mich.), presenting an inviting target to Republicans eager to deflect criticism from the role of the Reagan and Bush administrations in the scandal. The Balance-of-Power Question

Of no less concern to many lawmakers of both parties is the sensitive question of how far Congress should go, through precedents set by ethics cases, in constraining the authority of lawmakers to intercede for constituents with the executive branch of government.

To the extent that it limits such intervention through rulings in the Keating and D'Amato cases, Congress may be tilting the scales against itself in the 200-year struggle over the balance of power in Washington.

While little has been said -- or is likely to be said -- about the issue of congressional leverage on executive or regulatory agencies, key members of the ethics panel are beginning to voice concern over suggestions that their handling of the Keating Five is being influenced by savings and loan politics.

In opening remarks at this month's hearing on Durenberger, which also appeared aimed at the Keating case, Sen. Warren B. Rudman (R-N.H.), vice chairman of the panel, said the committee would not hesitate to drop charges against any senator even if it meant sailing against the political winds.

"No matter how contrary to the prevailing wisdom it may be, if a member has done nothing wrong, the committee will act accordingly," Rudman said. "The theory expounded by some that the committee will, because of the current political climate, take harsh action against Sen. Durenberger in order to prove it is tough is ludicruous."

While committee members have sought to keep the cases separate, shielding them from each other as well as from politics, others have drawn inevitable parallels. Even though each case must be decided on its merits, the Durenberger case will "establish a benchmark for the committee to meet" in the other cases, said Fred Wertheimer, president of Common Cause, the lobbying group that filed the initial complaint against the Keating Five. Denunciation Recommended

In Durenberger's case, Robert Bennett, special counsel to the Select Committee on Ethics, has recommended that the Senate "denounce" the lawmaker for evading its honoraria limits by a book promotion deal, for obscuring ownership of a Minneapolis condominium to get around lodging reimbursement rules and for violating gift restrictions in accepting free limousine service from special interests while on personal business.

The committee is expected to act on Bennett's recommendation, which Senate parliamentarians have characterized as a form of censure, after Bennett and Durenberger's attorney submit their final reports, possibly within a week or so.

Durenberger called no witnesses to challenge the 23-volume record assembled by Bennett, and, as Rudman put it during the hearings, "This case has never had a lot of disagreement about facts. It has had a lot of disagreement about what these facts mean."

Far less is known about where the panel is headed in the other cases. But it is understood that the factual situation is far more complicated, murky and disputed in these cases, especially the "Keating Five," who include Sens. Dennis DeConcini (D-Ariz.), John Glenn (D-Ohio) and John McCain (R-Ariz.) as well as Cranston and Riegle. Disputed Facts, Imprecise Rules

The rules they are accused of breaking are also less precise than the rules involved in the Durenberger case, especially the catch-all standard of the congressional ethics code that prohibits "improper conduct which may reflect upon the Senate."

In the complaint it filed last October, Common Cause cited this rule as well as provisions of the Code of Ethics for Government Service that bans lawmakers from accepting "favors or benefits under circumstances which might be construed by reasonable persons as influencing the performance of his government duties" and says they should not "discriminate unfairly by the dispensing of special favors or privileges to anyone."

The five senators are accused of intervening with federal regulators on behalf of Keating, head of American Continental Corp., which owned the Lincoln Savings and Loan in Irvine, Calif., at the same time Keating and his associates were raising more than $1.3 million for the campaigns and political causes of the five senators.

According to the allegations, they attended meetings with the regulators in April 1987, and Cranston and DeConcini intervened again in the spring of 1989, shortly before Lincoln was seized by regulators in a takeover that is expected to cost taxpayers at least $2 billion.

The senators have denied any wrongdoing, and several, especially Cranston, have begun vigorous public relations campaigns to defend themselves against the charges, denying critical points dealing with the nature and purpose of their intercession.

The intervention by the "Keating Five" appears to have varied considerably from senator to senator, as did the money they got from Keating, and Rudman has made a point of asserting that each case has to be considered individually. Although no one is saying so, this raises the possibility that cases against some of the five could be dropped as the committee moves to the second, next-to-final phase of its inquiry.

Moreover, committee members have expressed mounting concern over the potential unfairness of drawn-out proceedings, and it is possible, under Senate rules, to skip the second step and move directly to public hearings and a final verdict in cases where it is found that improper conduct may have occurred.