Senate Republicans on Tuesday tried to push through a bill that would have banned abortions after 20 weeks of pregnancy, but they were blocked by Democrats.

The Pain-Capable Unborn Child Protection Act needed 60 votes to advance but failed 54-42, reported The Hill. The bill passed the House earlier this year.

If enacted, it would ban abortions after 20 weeks except in cases involving rape, incest or when the mother's life is at risk.

Supporters of the 20-week bill argue that fetuses are individuals who can feel pain at early stages of development and therefore deserve protection, though the issue is still scientifically disputed, according to FactCheck.org.

"This is when unborn children can react, even recoil, to stimuli an adult would recognize as painful," said Senate Majority Leader Mitch McConnell, R-Ky. "This is when doctors even administer fetal anesthesia during surgery...So even if we differ on the larger abortion issue, can't we at least agree that children at this late stage of development deserve our protection?"

About 1 percent of abortions are conducted after 20 weeks, usually only to save a fetus or mother at serious risk, according to opponents of the bill.

"This is yet another Republican attempt to limit women's health care choices," said Sen. Mazie Hirono, D-Hawaii, reports USA Today.

The vote coincided with the arrival of Pope Francis, who is a leading voice against abortions and is expected to denounce the practice in an historic address to Congress on Sept. 24 at 10 a.m.

The vote also comes just eight days before the government runs out of money. Republican leaders in both chambers hope to find a way to pass a short-term funding bill to keep the government operational, but it's not clear if enough Republicans would back it unless the $500 million in annual federal funding for Planned Parenthood is removed, according to CNN.

Senate Majority Whip John Cornyn, R-Texas, has indicated that the Senate will soon move to vote on defunding Planned Parenthood.