Alexandria lawyer William G. Thomas, one of the premier lobbyists in the Virginia General Assembly, put his extraordinary influence on display today and got a legislative committee to reverse itself and approve an amendment sought by one of his clients.

But even the wiliest lobbyist needs a legislator to carry out his plan, and today, the official banner carrier for Thomas was Sen. Richard L. Saslaw (D-Fairfax).

The Senate Committee on Labor and Commerce, responding to intense lobbying in behalf of Blue Cross of Virginia, went into an emergency meeting this afternoon and approved the amendment sought by Thomas and offered by Saslaw.

By the time the whirlwind exercise was completed, Sen. William E. Fears (D-Accomack), the committee chairman, admitted on the Senate floor that he wasn't sure what had happened.

It was "great fun, pure theater," according to Sen. Dudley J. (Buzz) Emick Jr. (D-Botetourt), but Emick told his Senate colleagues that he was uncomfortable with "all the maneuvering going on . . . a bunch of people creeping around the edge" of the chamber.

"I don't understand this amendment," Emick said, "and on the premise -- unheard of by some here -- that if you don't understand it, you don't vote for it, I'm going to vote against it."

He asked its supporters to "say what this is really about," adding that he guessed there was "more to this than meets the eye."

Responded Fears: "If Senator Emick doesn't understand it, I'm sorry. I partly do."

On another part of the amendment, Emick asked, "What is the purpose?"

"I can't answer the question," Fears said.

Saslaw offered that "I guess I put this in there because . . . "

Despite those misgivings, the Senate approved the amendment 22 to 13, with five senators not voting. It could not be determined whether the five abstained because of the confusion, or for other reasons.

Today's behind-the-scenes drama was intensified because of competing midnight deadlines.

Both the Senate and House of Delegates were furiously enacting bills in the face of a mid-session deadline of midnight for passing legislation that had originated in their own chambers.

Action on the Blue Cross bill also needed to be completed before the end of the day, for a different reason.

The bill requires Virginia-based health insurance organizations to submit plans to the State Corporation Commission before they could merge. And the Blue Cross plans of Richmond and Roanoke had planned to merge Wednesday.

The legislation does not affect Blue Cross' 500,000 subscribers in Northern Virginia, who belong to a D.C.-based plan.

Saslaw's amendment eliminated a provision of the bill that would have required two-thirds of Blue Cross' members (stockholders) to also approve a merger. Saslaw said it was designed to allow quick action by the SCC, in the event that one of the candidates for merger was in financial trouble.

The amended bill got through both houses by sundown, and was being prepared for hand delivery to Gov. Gerald L. Baliles so that it could be signed into law in time to affect the merger.

But Baliles, who has not indicated whether he will sign it, bought some time for himself by getting the president of Blue Cross of Virginia, Norwood Davis, to agree to postpone the merger for two weeks so that the governor will have time to consider the bill.