Rep. Lee Zeldin announced Sunday a new proposal that would suspend the sale and marketing of Plum Island to private buyers and require an additional federal study of the sale.

The amended bill, which would mandate that the government outline alternative uses for the island, is expected to pass a House committee Thursday, Zeldin said at a news conference in Riverhead with local elected officials and environmentalists. The measure is expected to be voted on this year, he said.

Zeldin held a printed email from a real estate firm inviting potential buyers to tour Plum Island in June.

Under the bill “we will not see these emails that would result in the sale,” Zeldin said. “It’s a treasure that must be protected.”

The Republican congressman from Shirley introduced a bill last year to prevent the sale. He said that has stalled because it doesn’t direct the federal government on what to do with the land.

Congress in 2008 voted to close the existing Plum Island Animal Disease Center and move it to a new facility in Kansas. The government is selling the 840-acre, pork chop-shaped island off the tip of the North Fork to the highest bidder to pay for the new facility.

advertisement | advertise on newsday

Long Island and Connecticut elected officials and environmental groups have rallied to preserve the island, saying that the 90 percent of undeveloped land should be preserved because it has become a sanctuary for birds, sea turtles and seals.

Donald Trump in 2013 said he was interested in turning Plum Island into a “beautiful, world-class golf course,” noting then that he had spoken with local officials.

Zeldin said Sunday, “One presidential candidate had a different version for making Plum Island great again. We think it’s great as it is.” Zeldin said he has not endorsed any Republican candidate for president.

Southold rezoned the island in 2013 to prevent development there. Town Supervisor Scott Russell said Sunday that “zoning is the last line of defense, not the first one.”

Chris Cryder, special projects coordinator for Connecticut-based Save the Sound, said the first study is being led by the Department of Homeland Security. The second study, required in the Zeldin amendment, would be done by the federal Government Accountability Office. Cryder called it “an essential first step” to preserving Plum Island.

The second study would require the government to formulate a “comprehensive plan” for the future of the island, Zeldin said. Alternative uses for the island include transfer of ownership to another federal agency, the state or local government, or a nonprofit.

Zeldin said he told House Republican leadership the bill is his top priority.