Senate supporters of the administration's labor law revision bill, which had been given up for dead a month ago, said yesterday they will attempt to revive it in watered-down form.

But the so-called "bare-bones" labor bill ran into another round of opposition from conservatives, who threatened to try to kill it in committee by offering 500 or more amendments.

As redrafted by Human Resources Committee Chairman Harrison A. Williams Jr. (D-N.J.) and others, the new bill has been stripped of its title of "Labor Law Reform" and many of its most controversial features.

The bill no longer would prescribe deadlines for union representation elections or give unions access to company property during organizing campaigns or permit the government to withhold federal contracts from labor law violators.

But it would make a number of procedural changes aimed at expediting the handling of labor disputes and impose some new penalties for violating labor laws, including time-and-a-half back pay to workers illegally fired for union activity and civil fines of up to $5,000 a day for "willful" violations of workers' rights.

"Many of the improvements suggested by various senators have been incorporated into this bare-bones measure and I view it as a bill that could gain the support of all but a few members of Congress," said Williams in announcing that the bill will be considered tomorrow by the labor subcommittee and Friday by the full Human Resources Committee.

One of those who won't support it is Sen. Orrin G. Hatch (R-Utah), who wrote Williams saying he would have no alternative but to propose amendments in committee. A Hatch aide said the senator has 500 or more amendments ready.

If the bill gets out of committee, it could run into another Hatch-led filibuster on the floor. The legislation was sent back to committee in June after six unsuccessful attempts to break a filibuster that tied up the Senate for more than a month.

Union leaders, who were pushing hard for revival of the measure despite AFL-CIO President George Meany's concession last month that authentic "reform" was lost for this session of Congress, said they understand that proponents have more than the 60 votes necessary to break a filibuster on the scaled-down bill. But they conceded that 60 votes appeared likely before and then vanished when the roll calls came.