Despite pleas from Sen. Harrison A. Williams Jr. (D-N.J.) for a delay, Senate leaders yesterday scheduled a floor debate for Dec. 3 on a resolution to expel him from the Senate.

Williams, 61, convicted this spring of Abscam bribery and conspiracy charges, said yesterday he did not "intend to roll over and play dead for something I didn't do," and pledged to seek vindication on the Senate floor.

In a letter hand-delivered to his colleagues Monday, Williams, a 23-year member of the Senate, noted that the trial judge is still considering post-trial motions.

"The Senate could be rushing into an action which could be contrary to the final legal outcome of my case and irreversible by the time my innocence is proven," he wrote.

The letter was accompanied by a packet of materials, including a 21-page summary of Williams' defense; a three-page statement from Dr. Roger Shuy, professor of linguistics at Georgetown University, alleging 13 factual errors and four "misrepresentations through decontextualized emphasis" in an Ethics Committee report recommending expulsion; a copy of an affidavit signed by one of the trial jurors attesting that he would have voted for acquittal had he seen one of the documents withheld from the trial, and a series of newspaper reports raising questions about the tactics the FBI and the prosecutor used in the Abscam case.

"The response has been very favorable," said Williams spokesman Walter Gold. "A lot of the senator's colleagues have come up to him and said 'Gee, I didn't realize this.' " Gold declined to name any senators who have indicated they will support Williams on the floor.

The Ethics Committee had voted 5 to 0 this summer that Williams be expelled.

Senate Majority Leader Howard H. Baker Jr. (R-Tenn.) and Minority Leader Robert C. Bryd (D-W.Va.) scheduled the floor action yesterday after meeting with Williams.

A spokesman for the Ethics Committee said that a number of procedural questions relating to the floor debate--how long it will take and whether Williams will be entitled to legal counsel--remain to be worked out.

Williams was the only senator convicted in Abscam. Of the six House members convicted in the case, one was expelled, two resigned and the others were defeated when they ran for reelection