CARACAS (Reuters) - Venezuela’s opposition-led congress on Friday appointed alternative judges to the country’s Supreme Court, whose current pro-government members have been a bedrock of support for leftist President Nicolas Maduro.

Julio Borges (top R), president of the National Assembly and deputy of the Venezuelan coalition of opposition parties (MUD), attends a session of Venezuela's opposition-controlled National Assembly to appoint alternative judges to the Supreme Court in Caracas, Venezuela, July 21, 2017. REUTERS/Ueslei Marcelino

While widely seen as symbolic, the move raises the specter of the development of a parallel state. The top court has warned that the naming of the alternate judges is illegal, and they could be jailed.

Undeterred, opposition lawmakers swore in the 13 new judges and 20 substitute judges in a public plaza to combat what they say is oil-rich Venezuela’s slide into dictatorship under Maduro.

“We’re not backing down, Venezuela will have a Supreme Court of Justice and institutions at the service of the people and not at the service of whatever government is in power,” said opposition legislator Carlos Berrizbeitia during the ceremony, where the appointed justices were applauded and cheered on with shouts of “Bravo!”

Critics hold that the current Supreme Court justices were named illegally by the ruling Socialist Party and rushed in before the opposition took over the legislature in January 2016.

“They’re pirate magistrates named on the fly,” said opposition legislator Juan Requesens in a video streamed live on the Periscope service, which the opposition often uses given limited coverage of their activities on local television channels.

In a statement broadcast on state television later on Friday, the Supreme Court blasted the alternative judges who were named by the legislature.

“They’re undertaking crimes against the independence and security of the nation, in particular, in terms of crimes of treason and against the powers of the nation and states,” said Juan Jose Mendoza, the president of the top court’s constitutional chamber.

OPPOSITION CAMPAIGN

Even so, the government will not allow the congressionally appointed judges to unseat those already sitting on the Supreme Court.

Rather, the move was part of the opposition coalition campaign to pressure unpopular Maduro to hold a presidential election and abandon a new congress they fear would cement dictatorship. It followed nearly four months of violent street protests, an unofficial plebiscite against him last weekend and a national strike on Thursday.

Around 100 people have died in unrest that kicked off in early April, thousands have been arrested, and hundreds injured.

Two young men and one teenage boy died in disturbances related to Thursday’s strike, according to authorities. Over 360 people were arrested across the country on Thursday, according to the rights group Penal Forum.

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Venezuela’s second-largest city, Maracaibo, suffered looting and fires during the stoppage, according to local reports that have not been confirmed by authorities.

The opposition is vying to stop Maduro’s plan to on July 30 create a controversial super-legislature with powers to rewrite the constitution and supersede other institutions.

Maduro faces widespread pressure from abroad to abort the assembly, including from U.S. President Donald Trump who said on Monday he would take “strong and swift economic actions” if the Venezuelan leader went ahead with his plans.

Regional pressure is also rising. South America’s Mercosur trade bloc called for an end to violence in Venezuela in a joint statement on Friday.

Argentina, Brazil, Paraguay and Uruguay called on Venezuela to release political prisoners and offered to facilitate talks between Maduro and the opposition.