The Bush administration objected yesterday to a House subcommittee draft of legislation for a referendum on Puerto Rico's political future, warning that the bill might mislead and confuse voters.

Assistant Attorney General Stuart M. Gerson assured members of the House Interior subcommittee on insular and international affairs that the objections were not political, noting that the administration has endorsed the plebiscite idea. But the administration fears that the bill's definitions are unclear and might not be honored by a future Congress or administration, he said.

Resident Commissioner Jaime B. Fuster, a Democrat and Puerto Rico's nonvoting member of Congress, would have none of it. A former law school dean, Fuster charged that the criticism is little more than "a political statement" devoid of any substance that might help the panel draft the implementing legislation.

Fuster predicted later that the subcommittee would ignore the administration's advice and press its plan for a referendum in mid-1991 on the island's status.

The House bill would allow residents to vote on whether they wish the island to become a state, an independent republic or continue as an American commonwealth with "enhanced" status -- more self-government and federal aid. The House version would require a second vote by Congress to approve the Puerto Ricans' choice, while a similar measure under consideration in the Senate would put the verdict into effect automatically after the referendum.

Gerson said the administration endorses the Senate approach but would support the House bill if Congress approves it instead. He said, however, that the House bill is flawed because the subcommittee has allowed the three major parties on the island to help define the various options.

All the parties have engaged in "puffery," enlarging the powers the island would have under their option, Gerson said, and a future Congress or president might not be willing to grant all those powers.

For example, he said, commonwealth supporters had declared that the island would be "an autonomous body politic" that would be "joined in permanent union" with the United States. "It's difficult to know what this means," Gerson said.

The commonwealth definition also appears inconsistent and "highly ambiguous, and could become a source of great confusion and controversy," he added.

Neither independence nor statehood -- the option the administration endorses -- needs extensive definition, Gerson continued. He urged the committee to include a minimum of definitions in its bill.

"More fundamentally, because these provisions would be binding, we believe that their potential to be misleading and confusing is so great that they should not be included at all," Gerson said.

"We're not going to pay any attention," said Fuster, who supports commonwealth status. The subcommittee will pursue its intention to make its proposal mimic the longer Senate bill in part by condensing into a few paragraphs what voters might expect under each option, he said.

A bigger question, the resident commissioner added, is whether Congress will pass the legislation in time for the vote that all sides have agreed should be held next summer. "It's going to be dicey," Fuster said. "If we have one more delay, that's it."

The subcommittee hopes to mark up the bill in July, which probably means House floor action cannot be expected until September, he said.

The result could be that the House will have to schedule both floor action and a conference committee with the Senate over its sharply different bill in September. "It's going to be very difficult . . . an uphill battle," Fuster said.