The only hope for an Alaska lands bill this session lies in a Senate package close enough to the House version that a conference on the differences can be avoided, a key senator in the debate said yesterday.

Sen. Paul E. Tsongas (D-Mass.) said a conference would be vulnerable to "pre-conference, mid-conference and end-conference filibuster" from the two Alaska senators, who oppose what the Senate has done so far.

The measure, which would place more than 100 million acres of wild Alaskan territory in varying categories of environmental protection, has been under discussion off the Senate floor since a week ago yesterday, when debate broke down.

Tsongas was the environmentalist champion in the floor debate, proposing amendments to strengthen an Energy Committee bill offered by Sen. Henry M. Jackson (D-Wash.). But in closed-door negotiations designed to win Jackson's agreement, he has forged a compromise package that has come dangerously close to alienating not only the Alaska senators but also the Alaska coalition of 52 environmental groups.

A meeting with coalition leaders Tuesday, Tsongas told reporters, provided "no particular wear and tear on the grin muscles." Beth Johnson of the coalition confirmed that the group is still reserving judgment on what she called "the Tsongas-Jackson agreement."

Tsongas said Reps. Morris K. Udall (D-Ariz.) and John F. Seiberling (D-Ohio), key House members of the issue, had joined the ongoing talks. The question, he said, is reaching an accommodation "without everyone jumping ship. . . . The middle ground on this issue is very narrow."

Sen. Ted Stevens (R-Alaska) reiterated his position that although concessions to his viewpoint may have satisfied Jackson, they will not satisfy him. He said he would continue to push for the original committee provisions. h