The Senate Ethics Committee's deliberations on the conduct of the so-called Keating Five are expected to set standards for future dealings with political donors.

The committee, which was to begin private discussions Wednesday, is entering the toughest part of its 13-month investigation into the activities of Sens. Alan Cranston, D-Calif.; Dennis DeConcini, D-Ariz.; John McCain, R-Ariz.; Donald W. Riegle Jr., D-Mich.; and John Glenn, D-Ohio.The committee's three Republicans and three Democrats must decide whether the senators violated Senate rules when they intervened with thrift regulators on behalf of Charles H. Keating Jr., the former owner of the now-failed Lincoln Savings and Loan.

At the same time, the committee is expected to recommend standards governing senators' intervention with regulatory agencies on behalf of major political donors.

"There is not only outside pressure but pressure from within the institution to clarify the rules so members could have guidelines in which to operate," said one Senate source, speaking on condition he not be named.

The committee has before it thousands of documents and transcripts from two months of public hearings that ended two weeks ago.

The panel can dismiss senators from the case, vote to send letters rebuking their conduct or recommend either censure or expulsion by the full Senate.

One of the committee's six members, Trent Lott, R-Miss., has said he would be amazed if the panel didn't recommend that at least one senator be censured on the Senate floor.

Before a recommendation goes to the Senate, however, committee rules require that the defendant be given a list of charges against him and have a chance to respond.