A judge in Florida declined to temporarily block the state’s aggressive new congressional map on Tuesday, allowing it to remain as a lawsuit challenging it moves forward. The map could give Republicans four additional seats as they try to maintain control of Congress in the November midterm elections.

The voting and civil rights groups that sued this month argue that the map violates a state ban on partisan gerrymandering, known as the Fair Districts amendments, that voters passed in 2010. But Judge Joshua M. Hawkes of the Second Judicial Circuit in Tallahassee wrote in denying the temporary injunction that the groups had not sufficiently proven that their case was likely to succeed.

Judge Hawkes also disagreed with the plaintiffs’ argument that if the court temporarily blocked the new map, it should reinstate the previous districts. The administration of Gov. Ron DeSantis, a Republican, had argued that a majority-Black district included in the previous map would be unconstitutional under a recent Supreme Court ruling that weakened the federal Voting Rights Act.

Noting that he had to weigh both the plaintiffs’ argument that the new map violated Florida’s ban on partisan redistricting and the state’s argument that its previous map violated the equal protection clause of the U.S. Constitution, Judge Hawkes sided with the state, writing that “the potential partisan intent in the 2026 map is the lesser of the two evils.”

The plaintiffs said that they would appeal, though time is running short. Congressional candidates can begin qualifying for Florida’s Aug. 18 primary ballot this week, a deadline extended this year as President Trump pushed for Republicans across the country to take the highly unusual step of redistricting in the middle of the decade.

“Because Floridians of all political backgrounds are so clearly against partisan gerrymandering, we will exhaust all legal options to make sure a map this partisan does not last the rest of this decade,” Amy Keith, executive director of Common Cause Florida, one of the plaintiffs, said in a statement.

Judge Hawkes wrote in his ruling that the scant time before the primary was a reason to keep the new map, which Mr. DeSantis signed into law on May 4, given that “the election machinery of the state is already underway.”

“The primary is less than three months away, and the general less than six months,” he wrote. “The public interest weighs more in favor of certainty than a haphazard judicial mandate of discarded maps.”

Under the previous congressional map, which had been in place since 2022, Democrats held eight of the state’s 28 congressional districts; under the new map, they would be favored to win only four.

Republican lawmakers, who hold supermajorities in the State House and Senate, adopted the new map last month at the urging of Mr. DeSantis. Lawmakers were preparing to vote on it when the Supreme Court issued a long-awaited decision that weakened the landmark 1965 Voting Rights Act; the ruling set off a scramble across Republican-held Southern states to redraw voting districts.

The court found that Louisiana lawmakers had unconstitutionally relied on race when they drew a 2024 congressional map to include a second majority-Black district. Mr. DeSantis had predicted such an outcome and used it to justify redrawing Florida’s map, citing a majority-Black district in South Florida.

The state’s new map not only carved up that Democratic-held district, making other districts around it more Republican-leaning, but also did away with Democratic-held seats in the Tampa Bay and Orlando areas.

The case before Judge Hawkes, whom Mr. DeSantis appointed in 2020, did not center on race. Rather, three voting rights groups argued that the map violates the ban on partisan gerrymandering that Florida voters passed in 2010 under the Fair Districts amendments. The DeSantis aide who drew the new map told state lawmakers last month that he had done so based partly on the partisan breakdown of voters.

“This case is unusual, because the map drawer admitted on the public record that the districts were drawn with partisan data and without the need to comply with the Fair District amendment,” Christina Ford, a lawyer with Equal Ground, one of three groups that sued, said in a virtual court hearing in mid-May.

Lawyers for the DeSantis administration and for state lawmakers countered that the plaintiffs had not proven a partisan intent behind the new map, and Judge Hawkes agreed.

The defendants also argued that the state no longer needed to comply with the ban on partisan gerrymandering.

A Fair Districts provision allowing race to be used as a consideration when redrawing maps is unconstitutional, they maintained, and so the provision banning partisanship as a consideration should also be invalid.

“It is intertwined,” Mohammad O. Jazil, a lawyer for Florida’s executive officials, said in the court hearing.

In his ruling on Tuesday, Judge Hawkes wrote that at this early stage in the case, questions about the “constitutional viability” of the Fair Districts amendments would be “premature.”