Borrowing a controversial idea of the 1950s, Democratic National Chairman Charles Manatt is forming a new council of party luminaries, with himself as chairman, in an attempt to forge unified Democratic alternatives to Reagan administration policies.

Manatt's proposal, outlined in a three-page "confidential memorandum," has begun to provoke considerable interest, and a few questions of concern, among Democrats on Capitol Hill and elsewhere in Washington. It envisions a central council composed of no more than 30 leading Democrats, including House Speaker Thomas P. (Tip) O'Neill Jr., Senate Minority Leader Robert C. Byrd, and Manatt.

"All members should be astute politically, press-worthy, and command the respect of a significant group or groups of individuals," says the memo, which was prepared for the new party chairman by Harold (Hal) Kwalwasser, a Los Angeles attorney whom Manatt hired to design this new Democratic superstructure.

The memo was prepared for distribution to a handful of top party officials in the Democratic National Committee and on Capitol Hill.

Manatt's policy council would be serviced by an array of "advisory councils" for the various subject areas. And, apparently taking note of Washington's de facto division of talents, the memo cautions:

"Each group should be divided roughly equally between experts/thinkers and practicing politicians, particularly members of Congress."

From 1953 to 1955, the Democrats found themselves out of power both in the White House and on Capitol Hill. In that era, then-party chairman Paul Butler created a similar council apparatus to draft Democratic policies and denounce Republican policies -- only to find that he had created a major intramural controversy in the process.

The Democratic leaders in Congress -- Sam Rayburn in the House and Lyndon B. Johnson in the Senate -- refused to have anything to do with Butler's policy council. Officially, they took the position that the Democrats in Congress needed no help in fashioning policies. In fact, they were deep into the politics of coexistence, rather than confrontation, with the Eisenhower White House and the Republicans in Congress.

Butler's group was viewed then as seeking to steer the party through a series of liberal left turns on such matters as civil rights, while Rayburn and Johnson were trying to navigate less controversial middle roads. Among those who did serve on Butler's council were Sens. Hubert H. Humphrey, Stuart Symington, and John F. Kennedy. And among those who served on Butler's Democratic National Committee staff in those days was a dutiful young aide named Charles Manatt.

This time around, Manatt is paying careful attention to the consultation and courtship of the leading congressional Democrats. He first broached the idea of his Democratic strategy council at a meeting of the Democratic congressional leaders and the heads of the congressional campaign committees before the Easter recess, according to one Capitol Hill source. Manatt is said to have spoken of his proposal only in general terms in that session, the source said, but he is scheduled to review it in detail when the Democratic leaders reconvene May 4.

There is little disagreement among Senate and House Democrats that some sort of umbrella unit would be helpful in countering the Reagan administration policies and especially the public relations advantage that any White House has. Democrats have too often seemed in disarray since the Republicans took control of the White House and the Senate, and the party leaders remain divided over the alternatives to Reagan's proposals.

But there is some question, according to a number of Democratic aides and advisers, as to just what that overall party structure should do and who should run it. And there is some question as to whether O'Neill and Byrd will go along with Manatt's plan, according to these sources.

"To tell you the truth, I just don't know," said a source close to O'Neill. "Tip really didn't have any reaction to it at that first meeting [of Democratic leaders]."

A source close to Byrd, meanwhile, said that the Senate Democratic leaders "really hasn't focused on it yet." The source said that Byrd probably would have no objection to Manatt's charing the council, but added that he might have some question as to the council's role in drafting Democratic policy.

"I don't know that this will be the organization in which Democrats sit down and say what they stand for," said this source. "The House and Senate is where the policy must be implemented."

Over at the Democratic National Committee, Manatt says he does not believe he will have the sort of problems with O'Neill and Byrd that Paul Butler had three decades ago with Rayburn and Johnson. "The critical difference is that that was the era of civil rights," Manatt said. "The idea now is to develop alternative positions -- a bubbling-up of new ideas."

In his memo for Manatt, Kwalwasser proposed that the new council meet monthly. "Prior to each meeting," the memo said, "the DNC [Democratic National Committee] staff, along with the staff of the speaker and the minority leader, will prepare a factual summary of recent Republican moves and those that can be expected in the near future. They will then set out a series of possible responses for consideration."

Kwalwasser also emphasized that the advisory councils' work would be of a political, rather than conceptual nature. ". . . While the thinkers on the advisory councils should produce work product for consumption by other council members (and in some cases for Democrats generally), it should be limited to identifying problems and solutions relevant to the campaigns."

Manatt has asked the party's new executive director, Eugene Eidenberg, formerly of the Carter White House, to supervise the consultations on the project with congressional leaders, governors, mayors, and other Democratic officials. Eidenberg says he does not yet know Byrd or O'Neill personally, but vows that he will soon. He explains:

"In this town, when you put something together in the wrong way, it'll hurt you substantively later."