LOS ANGELES (AP) — Gov. Jerry Brown is dropping his attempt to shield California's high-speed rail project from possible environmental challenges — at least for now.

State lawmakers and environmental groups have been told the governor won't pursue legislation his office had begun circulating earlier this month, several media outlets reported Thursday. That legislation would have blocked judges from issuing work-stopping injunctions in many environmental lawsuits.

It could have affected lawsuits filed by Central Valley farm groups, who argue that the proposed $68 billion project could harm agricultural areas.

Brown dropped his effort in the face of opposition from environmental groups, but those groups say he could revive the plan later.

Brown's decision comes as legislators prepare to consider appropriating $6 billion to begin construction of the rail system as early as December.

Sierra Club California director Kathryn Phillips told the Los Angeles Times that Brown's decision means her organization could now support the appropriation, as it did the original bond proposal approved by voters in 2008. She said high-speed rail is the sort of major project that the state's environmental laws were designed to review.

A Brown adviser sent an email Wednesday to environmentalists and transportation advocates, saying that the administration would drop the attempt, but that it could try again later, Phillips told The Sacramento Bee.

"So I feel like I can sleep well tonight, and there will be another day when we will have to struggle with how we can ensure that we protect environmental quality," Phillips told the Bee.

Gil Duran, a spokesman for the governor, declined comment Thursday.

Sen. Joe Simitian, D-Palo Alto, told the Times there was not much support in the Legislature for limiting environmental challenges.

California High-Speed Rail Authority chairman Dan Richard had raised the possibility of giving the project some immunity from injunctions in his comments to a Senate committee. Brown followed by advancing legislation that would make it more difficult to win court orders stopping work on the project.

The proposed legislation would have made the restrictions retroactive to Jan. 1, 2012, potentially limiting a lawsuit filed by farm bureaus in several Central Valley counties. The suit argues that there was an inadequate environmental review of the plan to build high-speed rail between Merced and Fresno.

Also Thursday, Richard released a video address on YouTube describing the project as a way to not only bring high-speed trains to California, but to improve traditional mass transit in urban areas.