TALLAHASSSEE, Fla. -- The Florida Supreme Court, in a sharp rebuke to the Republican-controlled Legislature, refused Thursday to throw out a lawsuit that contends legislators ignored new standards while drawing up legislative districts.

The Legislature wanted the state's high court to block a challenge to last year's new map for state Senate districts.

But the court - by a 5-2 vote - ruled that blocking the lawsuit would go against the will of voters who adopted two constitutional amendments that imposed new rules for redistricting.

The "Fair Districts" amendments approved in 2010 mandate that legislators can't draw legislative or Congressional districts intended to protect incumbents or members of a certain political party.

"This interpretation would directly contravene the purpose of the 2010 amendment and undermine the will of the voters in placing more stringent standards on the Legislature," wrote Justice Barbara Pariente for the majority.

The dispute before the court dealt with the complicated process now in place to draw up new districts.

Every 10 years state lawmakers draw new legislative and Congressional districts based on updated U.S. Census information.

The Supreme Court last year initially rejected the state Senate map - but then approved a revised version after legislators held a special session to adopt a new map. Legislative lawyers argued that the court's approval during this this 30-day review period precluded any future lawsuits.

But Thursday's ruling states that the initial review was limited and did not include any facts or evidence.

Justice Charles Canady dissented and argued that the state constitution makes it clear that the Supreme Court's initial approval was "binding" and should be followed.

"It is plainly designed to conclusively determine and settle once and for all the validity of a redistricting plan under state law," Canady wrote.

The court's decision means that the lawsuit brought by several groups, including the League of Women Voters, will go forward now in a lower court.

"The public has a right to know whether their elected leaders are upholding the constitution and today that right has been vindicated," said Adam Schachter, one of the attorneys representing the groups challenging the current state Senate districts. "This is an important victory for Floridians who voted overwhelmingly to change the ways the Legislature draws redistricting maps."

A spokeswoman for Senate President Don Gaetz said he was disappointed with the decision but added that he predicted the state Senate maps would withstand the legal challenge. New districts for the Florida House have already been ruled valid and are not the subject of any legal challenges.

Raoul Cantero, a former state Supreme Court justice representing the Senate, said the ruling would "increase taxpayer expense by requiring yet another round - and perhaps endless rounds - of litigation to defend a redistricting map that the court had already considered and approved."

The Legislature in the last year has spent nearly $1.37 million on attorney fees and other legal costs fighting the redistricting lawsuits. More than $900,000 has been spent by the Senate.

The lawsuit has already turned up documents showing top GOP officials met in late 2010 to brainstorm redistricting with political consultants and legislative staffers. Lawyers for the League are pushing to interview legislators about why they drew districts a certain way.

Legislative lawyers, meanwhile, have unearthed emails showing that "Fair Districts" backers worked on a map submitted as part of one lawsuit where the "underlying goal" was to increase "safe Democratic seats" and the number of "competitive seats."

Republicans hold a 26-14 advantage in the Florida Senate, a 76-44 edge in the state House and a 17-10 advantage in the state's congressional delegation even though there are more registered Democrats than Republicans in the state and President Barack Obama carried the state.