LITTLE ROCK, Ark. (AP) — Arkansas Gov. Mike Beebe on Monday vetoed what would have been the most restrictive abortion ban in the nation, telling lawmakers that outlawing the procedure as early as 12 weeks into a pregnancy would be unconstitutional.

Beebe used the same reasoning as he did last week while vetoing a 20-week abortion ban — a veto lawmakers quickly overrode. The Democratic governor said the Arkansas Legislature’s new Republican majority was violating the U.S. Supreme Court’s 1973 Roe v. Wade decision, which legalized abortion until a fetus could survive outside the womb — generally 22 to 24 weeks. The measure would ban most abortions once a fetal heartbeat can be detected using an abdominal ultrasound, which is generally 12 weeks into a pregnancy.