NASHVILLE (AP) — Tennessee Gov. Bill Lee on Monday signed one of the strictest abortion bans in the country, and a federal judge quickly blocked the measure.

U.S. District Judge William Campbell in Nashville opted to wait for the bill to become law to rule on whether to block the bans included in it. In granting the temporary restraining order Monday, he wrote that he's "bound by the Supreme Court holdings prohibiting undue burdens on the availability of pre-viability abortions."

Supporters of these type of bills hope lawsuits over them head to an increasingly conservative U.S. Supreme Court in hopes of ending the constitutional right to abortion protected under the 1973 Roe v. Wade landmark ruling.

Lee, who announced the legislation in January alongside Republican lawmakers, said during a livestream from his desk Monday that he was signing "arguably the most conservative, pro-life piece of legislation in the country."

Plaintiffs seeking to block the law quickly let the court know it was signed and became effective immediately, "meaning that nearly all abortions in Tennessee have been criminalized." The court's ruling followed shortly after, keeping the law blocked pending a July 24 hearing.

Planned Parenthood, the American Civil Liberties Union and the Center for Reproductive Rights filed the lawsuit hours after the bill passed.

Under the law, abortions are banned once a fetal heartbeat is detected — about six weeks into pregnancy, before many women know they're pregnant. Similar legislation has been enacted in other states, such as Mississippi and Georgia, but has been blocked by legal challenges.

In the waning moments of the annual legislative session last month, state lawmakers passed the bill as most Tennesseans were asleep and largely unaware the GOP-dominant General Assembly had taken up the controversial proposal. Public access to the Capitol was limited due to COVID-19, with the Senate not allowing the public to watch from the chamber gallery.

The bill's passage shocked Democratic lawmakers and reproductive rights advocates.

"Today's ruling ensures that for now, people in Tennessee can continue accessing safe, legal abortion in their home state," Alexis McGill Johnson, president and CEO of Planned Parenthood Federation of America, said in a statement. "But while we can enjoy a moment of relief today, we can't forget that legislators passed this dangerous abortion ban in the dead of night without any public input."

On Monday, House Democratic Caucus Chairman Mike Stewart said the law "will ultimately cost taxpayers millions in legal fees to defend."

The law also includes a prohibition on abortion based on race, sex or diagnosis of Down syndrome. The court blocked that provision as well.

The court's action leaves in place some abortion requirements in the new law, though those don't further ban the procedure in Tennessee.

One spells out requirements for medical professionals to offer to show the pregnant woman an ultrasound and let her hear sounds of a fetal heartbeat before she consents to have an abortion.

Another requires medical providers and the state Department of Health to provide information about the possibility of reversing medication abortions. Opponents of the requirement say the reversal method is scientifically unproven and disputed in the medical community.