CARACAS, Venezuela -- Venezuela's government-stacked supreme court has moved to strip a key power from the country's increasingly defiant chief prosecutor, moving itself to impose her deputy: a loyalist who was sanctioned by the U.S. in 2015 for her role prosecuting some of President Nicolas Maduro's most vocal opponents.

The court's decision to name Katherine Harrington to the post, effectively making her the nation's No. 2 law enforcement official, came a day before Tuesday's scheduled debate on whether to remove chief prosecutor Luisa Ortega Diaz of immunity from being tried for unspecified irregularities.

As Venezuela's political crisis has deepened amid almost-daily protests, Ortega has emerged as Maduro's most-feared critic. In April, the once-loyal leftist broke with the government over its decision to strip congress of its last powers, and she has made common cause with right-wing opponents in blasting Maduro's plans to rewrite Venezuela's 1999 constitution.

The constitution says the chief prosecutor, who is legally semi-autonomous, has power to name her own deputy, with confirmation by congress. Lawmakers on Monday re-confirmed Ortega Diaz's choice as deputy to his post after he was removed by the high court last week.

The court also has attacked Ortega Diaz's authority by throwing out her order for the former head of the national guard to testify about alleged human rights abuses during the crackdown on the protests, which have left at least 80 dead. It has also limited her powers to investigate abuses, which are shared with the nation's ombudsman.

The almost daily assault has only emboldened Ortega, who was warmly applauded Monday during an address by opposition lawmakers until a few months ago considered her Maduro's jailer.

"My role as chief prosecutor requires that I assume the first line of defence of our republican state," she said in a video address to the nation on Monday.

She said that "in the face of the attacks and threats hanging over the country," her agency is "perhaps one of the few democratic windows that are left open." She said it "won't be intimidated or give up the rights and freedoms of Venezuelans without a fight."

Harrington, a career prosecutor, was sanctioned by the Obama administration in 2015 for her role pursuing charges against some of Maduro's most vocal opponents. They include the jailing of Caracas Mayor Antonio Ledezma on charges he plotted to overthrow Maduro and a case against former lawmaker Maria Corina Machado that was based on emails later shown to be fraudulent.