A federal judge on Monday temporarily blocked a new North Dakota law that bans abortion when a fetal heartbeat is detected — as early as six weeks into pregnancy, calling the law “clearly invalid and unconstitutional.”

U.S. District Judge Daniel Hovland in Bismarck granted a temporary injunction Monday that blocks the Aug. 1 enactment of the law that abortion rights advocates call the most restrictive in the nation.

“There is no question that (the North Dakota law) is in direct contradiction to a litany of United States Supreme Court cases addressing restraints on abortion,” Hovland wrote. ” (It) is clearly an invalid and unconstitutional law based on the United States Supreme Court precedent in Roe v. Wade from 1973 … and the progeny of cases that have followed.”