KIAWAH ISLAND — The long legal fight over plans to build homes on a strip of land at the southern tip of the island is heading back to court.

A year after a state Supreme Court blocked developers from building 50 homes on Captain Sam’s Spit, conservationists are appealing the town of Kiawah Island’s decision last month to grant developers an extension to update their plans.

The lawsuit argues that the plan, known as a preliminary plat, doesn’t qualify for the extension the Planning Commission approved, and even if it did, developers missed the legal deadline to ask for it.

“We must do everything we can to ensure that the Spit remains a protected resource for current and future generations of South Carolinians who benefit from having such a valuable natural area to recreate in and enjoy,” said a statement from Amy Armstrong, executive director at South Carolina Environmental Law Project, which filed the appeal in Charleston County circuit court this month on behalf of the nonprofit group Preserve Kiawah. “The plan cannot even be accomplished as proposed because of the significant changes to the Spit over time, as anyone who visits the Spit frequently is keenly aware.”