A proposal to build a new wind port on Sears Island is facing a potential setback following a House vote Tuesday to reject a bill seeking to grant the project an exemption from coastal sand dune regulations.

The House voted 80-65 against the bill, with members of both parties voting on either side. It will now head to the Senate.

The bill sponsored by Rep. Gerry Runte (D-York) seeks to allow the state to begin to apply for the permits needed to build a new wind port on Sears Island. During House debate Tuesday, Runte said the project will disturb a man-made sand dune that’s less than one-third of an acre in size.

In addition, the bill seeks to conserve other sand dunes on the island and set aside $1 million for sand dune conservation statewide.

He emphasized the economic benefits of a new port, saying it will bring 1,000 jobs to an area where many people are living “paycheck to paycheck.”

“It will be a lifeline to local workers,” he said.

Yet others, including Rep. Reagan Paul (R-Winterport) said Sears Island is a large undeveloped island with wetlands and other areas that should not be disturbed. Instead, nearby Mack Point, which is already an industrial area, should be the site of the new port, she said.

“Let’s exercise caution,” she said. “Rushing leads to mistakes.”

House Minority Leader Rep. Billy Bob Faulkingham (R-Winter Harbor) questioned whether environmental laws have value if they can be skirted by the Legislature.

“Sears Island is not the right place for this,” he said.

When Gov. Janet Mills announced the state’s choice of Sears Island in February, she said her administration spent two years comparing Mack Point to Sears Island.

She emphasized that only part of Sears Island will be used for the port, with the remaining two-thirds conserved for recreation and wildlife. A major reason to pick land on Sears Island is that the state already owns it and it has been earmarked as a potential site for commercial development for more than 10 years, she said during the Feb. 20 announcement.

It will also not require as much dredging to make it usable for the types of ships that will need access to the site.

The port would serve as a place to build, stage, assemble and maintain the operations of a floating offshore wind site.

Groups as diverse as the Maine State Chamber of Commerce, Maine Conservation Voters and the Maine AFL-CIO applauded the decision to choose Sears Island, saying that the state must take action now to tackle climate change.

Some Democrats who spoke on the House floor Tuesday said they found it difficult to support providing an exemption from one type of environmental law to benefit a different environmentally friendly project.

“I cannot cast a vote that these sand dunes are less important than other sand dunes,” said Rep. Jan Dodge (D-Belfast).

Yet others voted in support despite their misgivings.

“The sad facts are most of the dunes will be gone in 10-15 years if we do nothing,” said Rep. Valli Geiger (D-Rockland). “It is with great reluctance that I will vote for this bill.”

Correction: An earlier version of this story incorrectly characterized the Maine Audubon position on the project. The group supports some, but not all, aspects of the wind port.