More than 1,000 students apply every year to win a coveted spot in one of Miami-Dade’s premier magnet schools — the marine-themed MAST Academy near the entrance to exclusive Village of Key Biscayne.

Now, an $18 million deal being considered by the village and the school district that would allow students who live in Key Biscayne — which has no high school — to bypass the lottery to attend the prestigious waterfront campus on Virginia Key starting next year, has sparked a firestorm.

The proposal has angered many students, parents, teachers and alumni, who feel Key Biscayne parents are pushing for access behind the village’s offer to pay half of the expansion — up to $9 million— and shoulder the upfront liability. They also fear that the dramatic expansion and onslaught of students will alter the environment at the close-knit school.

The proposal would eventually add 1,100 seats to MAST, which currently enrolls about 560, bringing the total student population to as much as 1,700 students.

The extra seats would go first to Key Biscayne residents who meet the academic, attendance and conduct requirements for the magnet school. Superintendent Alberto Carvalho said potentially additional seats could be added to the county-wide lottery.

News of the proposal became public last week, as the school year ended. Since then, anger has spread throughout the MAST Academy community.

On social media and email, alumni, students and parents have blasted the proposal, saying it means the end for the school, known as much for its academic rigor as its close-knit community.

MAST Academy routinely ranks among the top public schools in the state and the country. Because of its success, the district has franchised the name and opened other MAST magnets

“They’re buying their way in. That’s the way it looks to everybody and that’s the way it looks to me, too,” said Joseph Zawodny, who was the original lead teacher at MAST, which opened in 1990.

Zawodny said the idea of the magnet came from an inner city marine project which worked with students from neighborhoods like Liberty City. The magnet’s goal was to take students from across the county and expose them to a culturally and academically rich environment, all centered on marine studies. “That’s what bothers me. We’re forgetting the mission of what we’re there for.”

Carvalho said the proposal solves two problems at a low cost to the district: It gives a high school option to Key Biscayne students who are now zoned to attend miles-away Coral Gables Senior High and it eases overcrowding and upgrades Key Biscayne K-8 Center — with the village shouldering the upfront cost and paying half the final bill for the cash-strapped district. The plan’s first phase starts next school year with two portables to be set up at MAST for eighth and ninth graders.

The controversy comes to a head this week. A town hall meeting at MAST Academy at 5 p.m. Tuesday will address the expansion. Later, at 7 p.m., the Key Biscayne Village Council will take up the proposal. It goes before the Miami-Dade School Board on Wednesday.

Tosca Lichtenheld, who graduated in 2010 and now is a chemistry major at the University of Chicago, said she was shocked when she learned of the plan to open the school up for Key Biscayne students without considering the impact on current students.

“It had been considered in many ways how this would affect the Key Biscayne community and the Key Biscayne K-8 Center. It had never been considered how it would affect the MAST community,” she said.

Michael Bax, whose sons attend MAST, fears the school will suffer. “We’re not elitist. The school is an elite school because of its elite academics and because people worked to get there and work to stay there.”

Meanwhile, parents whose students attend the overcrowded Key Biscayne K-8 Center say their campus needs help the deal will provide. “The dilapidated part of the school building is 50-something years old,” said Manual Cambó, head of the school’s Parents, Teachers and Students Association.

The district does not have the money to upgrade and expand the K-8 center or build a new high school, Carvalho said.

Board Member Raquel Regalado, who represents the district, said the expansion of the academy will not “dilute the quality of MAST.”

“It’s going to give the area residents an ability to attend and to participate in the MAST community ... “It’s not something that’s going to hurt MAST. I think it’s going to enhance it.”