Louisiana's attorney general said he got legal clearance on Monday to keep blocking a measure protecting gay and transgender workers in the state, one of a growing list of disputes over LGBT rights heating up across the south.

Jeff Landry, a Republican, has been caught in a confrontation with the state's Democratic Governor John Bel Edwards, who brought in measures in April banning state agencies from discriminating against gay and transgender people.

Landry, who has described himself as a "campaigner for conservative family values", started blocking several new contracts the state signed with companies that included those protections.

He accused the governor of overstepping his authority and largely steered clear of directly discussing gay rights. But his stance has won support from conservative lawmakers and groups across the state, including the Louisana Family Forum.

Edwards brought a lawsuit trying to prevent Landry from blocking the contracts. But Landry said a state judge in Louisiana's capital Baton Rouge dismissed that lawsuit on Monday.

"All along, I have stated my intention to put Louisiana's best interests forward as I serve as the state's chief legal officer," Landry said in a statement. He would "not cower to executive overreach," he added.

There was no immediate comment from the governor. But a member of his legal team told the judge they would appeal, The Advocate newspaper said.

Courts have become the frontline in a battle over gay and transgender rights raging across the United States.

Four Massachusetts churches filed a lawsuit last week asking to be exempted from a state law that requires public places to allow transgender people to use bathrooms in line with their gender identity. 

Late last month California Governor Jerry Brown signed a bill opening single-stall public restrooms to anyone, regardless of gender.