The Texas House of Representatives approved sweeping abortion restrictions on Tuesday, including a ban on most abortions after 20 weeks of pregnancy and tougher standards for abortion clinics.
The vote of 98-49 came after a full day of sometimes emotional debate. Before the measure can head to the state Senate, it needs a final vote from the House, which is expected on Wednesday.
The House approved the same proposal during a previous special session of the legislature, but it failed to pass in the Senate after Democratic Senator Wendy Davis staged an 11-hour filibuster that gained national attention.
Texas Governor Rick Perry, a Republican who opposes abortion, called lawmakers back to Austin for a second special session to reconsider the proposal.
Since the second special session began on July 1, thousands of Texans have packed the Capitol to testify at hearings and hold rallies and marches. To distinguish themselves, supporters of the bill wore blue and opponents donned orange clothes.
After the vote on Tuesday, bill opponents packed the area outside the House chamber, chanting "Defense! Defense!" to cheer on lawmakers who voted against the bill and were emerging from the legislative chamber.
During the debate on Tuesday, Representative Jason Villalba, a Republican whose wife is expecting a baby boy, spoke passionately in favor of the bill while showing his colleagues a sonogram picture of "my son."
"We fight this fight because of innocent human life," he said.
The 20-week provision - a version of which has been passed by a dozen states - is based on controversial medical research that suggests a fetus starts to feel pain at that point in the pregnancy.
Bill opponent Representative Senfronia Thompson, a Democrat, unsuccessfully proposed an amendment to exempt victims of rape and incest from the 20-week provision.
"I don't think that you want to traumatize (a) young woman by making her carry a child that her stepfather has impregnated her with, or her father," Thompson said.
A special session of the Texas legislature can last up to 30 days.