State Sen. William Ligon, R-Brunswick, withdrew support from an amended version of his own anti-Common Core legislation Wednesday, a sharp reversal for a bill that seemed on a swift path to approval only two weeks ago.

Ligon’s opposition now makes it unclear what will happen with Senate Bill 167, which would have prohibited Georgia from testing students on material tied to any set of national standards like Common Core.

The House Education Committee is scheduled to discuss the bill later today. It passed the Senate by a vote of 34-16 and, having the support of Gov. Nathan Deal, seemed on its way to becoming law.

But teachers and education groups, arguing that SB 167 would force the state to adopt a third set of standards in the past 10 years, lined up against the bill, and it was altered when it reached the House Education Committee.

The amended version of SB 167 now would allow Georgia to test students on material tied to national academic standards, and it changes a provision that would have given local school districts the ability to essentially opt out of Common Core while the state Board of Education and an advisory panel review whether Georgia should remain in Common Core.

“The bill needs to make it clear Georgia will not participate in nationalized standards,” Ligon said to a roomful of Common Core opponents.

Education groups said SB 167 would threaten federal funding, throw a wrench into the state’s teacher evaluation system and stifle education research aided by the collection and sharing of student academic data.

Opponents of Common Core, who supported the original version of SB 167, said the standards are weaker than the ones Georgia used before and would allow the federal government to dictate what is taught in the state.

The debate is a politically difficult one for Deal, who is trying to fend off two GOP challengers as he seeks re-election. Two important GOP constituencies — anti-Common Core Tea Party activists and pro-Common Core business interests — are on opposite sides of the debate.