A deeply divided supreme court has allowed a Texas law that bans most abortions to remain in force, stripping most women of the right to an abortion in the nation’s second-largest state.

The court voted 5-4 early on Thursday to deny an emergency appeal from abortion providers and others that sought to block enforcement of the law that went into effect Wednesday.

The Texas law, signed by Republican governor Greg Abbott in May, prohibits abortions once medical professionals can detect cardiac activity, usually around six weeks and before most women know they’re pregnant.

It is the strictest law against abortion rights in the United States since the high court’s landmark Roe v. Wade decision in 1973 and part of a broader push by Republicans across the country to impose new restrictions on abortion. At least 12 other states have enacted bans early in pregnancy, but all have been blocked from going into effect.