JACKSON, Miss. (AP) — Mississippi senators have passed the final version of a bill that would ban most abortions once a fetal heartbeat can be detected, about six weeks into pregnancy.

Republican Gov. Phil Bryant promises he will sign the bill, which will give Mississippi one of the nation's most restrictive abortion laws. The 34-15 Senate vote Tuesday was largely along party lines, with most Republicans voting yes and most Democrats voting no.

Efforts to pass similar bills are underway in several states, including Georgia and Tennessee. Abortion-rights supporters are expected to sue to try to block such laws.

Abortion opponents are emboldened by a conservative majority on the U.S. Supreme Court and are seeking a case that could challenge the high court's 1973 decision that legalized the procedure nationwide.

The Center for Reproductive Rights is urging the governor to veto the bill.

The following statement is from Elisabeth Smith, chief counsel at the Center for Reproductive Rights.

“This law would ban abortion before most women know that they’re pregnant. Already, Mississippi has a slew of abortion restrictions and only one abortion clinic, making it nearly impossible to access abortion before six weeks of pregnancy.

Just months ago in a case we filed on behalf of Mississippi’s only abortion clinic—Jackson Women’s Health Organization—a federal court struck down Mississippi’s attempt to ban abortion after 15 weeks, calling it a waste of tax payer money and a transparent attack on women’s health. This new prohibition, at an even earlier stage of pregnancy, is blatantly unconstitutional and we have called on Governor Bryant to veto it. If he does not, we are ready to take Mississippi to court to protect all women in the state.”