By Corrie MacLaggan
AUSTIN, Texas (Reuters) - A Texas lawmaker who was a single mother at the age of 19 and is now a rising star of the state Democratic party was attempting to block a Republican drive for sweeping new abortion restrictions on Wednesday by speaking continuously for 12 hours.
The filibuster by state Senator Wendy Davis, 50, could derail a proposal including a ban on abortion after 20 weeks of pregnancy. She must talk until midnight (0500 GMT), when a 30-day special session expires.
But Texas Republican Governor Rick Perry, a strong opponent of abortion, could revive the proposal by calling another special session of the legislature.
If the filibuster fails and the Senate approves the proposal, Texas is virtually assured of becoming the 13th state in the nation and by far the most populous, to impose a ban on abortion after 20 weeks.
The proposal also calls for stricter standards for abortion clinics, which opponents said would force nearly all the state's abortion clinics to close or be completely rebuilt.
Davis said the abortion restrictions would be the latest in a "war on women" in Texas, using a criticism leveled at Republicans nationally in the 2012 election.
During the filibuster on Tuesday, she read a stream of messages of support she said had come from women around Texas.
Davis has used the filibuster to frustrate majority Republicans before, temporarily blocking approval of education funding cuts in 2011.
Republican supporters of the tighter regulation of abortion clinics said they would protect the health of women, and the ban on late-term abortions would protect the fetus based on controversial research that suggests pain is felt by 20 weeks of development.
The U.S. Supreme Court legalized abortion nationwide in 1973, but conservative states have enacted laws in recent years that seek to place restrictions on the procedure, especially on abortions performed late in pregnancy.
A Philadelphia jury last month convicted abortion doctor Kermit Gosnell of murdering three babies during abortions at a clinic in a high-profile case that focused national attention on late term abortions.
Earlier this month, the Republican-controlled U.S. House of Representatives passed a bill banning abortions 20 weeks after fertilization. The measure is extremely unlikely to become law because Democrats control the U.S. Senate and the White House.
Twelve states have passed 20-week bans, including two states where the bans take effect later this year, according to the Center for Reproductive Rights. Courts have blocked the bans in three of the 12 states - Arizona, Georgia and Idaho.
The Texas proposal would allow exemptions for abortions to save a woman's life and in cases of severe fetal abnormalities.
(Reporting by Corrie MacLaggan; Editing by Greg McCune and Lisa Shumaker)