WASHINGTON (Reuters) - The U.S. Federal Communications Commission is expected to publish on Thursday its December order overturning the landmark Obama-era net neutrality rules, two sources briefed on the matter said Tuesday.

FILE PHOTO - Federal Communications Commission (FCC) hearing room is seen in Washington February 26, 2015. REUTERS/Yuri Gripas

The formal publication in the Federal Register, a government website, means state attorneys general and advocacy groups will be able to sue in a bid to block the order from taking effect.

The Republican-led FCC in December voted 3-2 to overturn rules barring service providers from blocking, slowing access to or charging more for certain content. The White House Office of Management and Budget still must sign off on some aspects of the FCC reversal before it takes legal effect.

Congressional aides say the publication will trigger a 60-legislative-day deadline for Congress to vote on whether to overturn the decision. U.S. Senate Democrats said in January they had the backing of 50 members of the 100-person chamber for repeal, leaving them just one vote short of a majority.

Even if Democrats could win a majority in the Senate, a repeal would also require winning a vote in the House of Representatives, where Republicans hold a larger majority, and would still be subject to a likely veto by President Donald Trump. Democrats need 51 votes to win any proposal in the Republican-controlled Senate because Vice President Mike Pence can break any tie.

On Friday, a coalition of more than 20 state attorneys general and advocacy groups agreed to withdraw a protective petition filed in January that sought to preserve the right to sue.

Amy Spitalnick, a spokeswoman for New York Attorney General Eric Schneiderman, said the office reached an agreement to withdraw “the original petition and will simply refile it once the final rule is published. Either way, our coalition of AGs is taking the FCC to court to challenge its illegal rollback of net neutrality.”

The December FCC order will be made public on Wednesday and formally published on Thursday, the sources said. A spokesman for FCC Chairman Ajit Pai did not immediately comment.

The approval of Pai’s proposal marked a victory for internet service providers like AT&T Inc, Comcast Corp and Verizon Communications Inc and hands them power over what content consumers can access.

Earlier this month, technology companies including Alphabet Inc and Facebook Inc threw their weight behind the congressional bid to reverse the Trump administration’s plan to repeal Obama-era rules designed to protect an open internet.