CARACAS, Venezuela (AP) — Venezuela's opposition is calling a Supreme Court decision that bars four recently-elected lawmakers from taking their seats in the National Assembly part of a "judicial coup" and has vowed to uphold the voters' will when a new session starts next week.

The high court released a decision late Wednesday suspending the inauguration of four of the lawmakers declared winners after the opposition swept Dec. 6 legislative elections. Three are anti-government and one is a member of the ruling socialist party. The ruling comes in response to a challenge filed by supporters of the socialist party. The court did not explain the legal justification behind its decision.

The ruling could undermine the opposition's newly won two-thirds legislative "super-majority" and limit its power.

Opposition leaders are pledging that the barred lawmakers will attend the first session of the new congress on Jan. 5. Lawmaker Julio Borges, one of two favorites to be the next assembly president, said President Nicolas Maduro could not be allowed to overturn the will of the people.

"The National Assembly represents the sovereignty of the people, and the president is trying to violate that using a biased court," he wrote on Twitter. "On Jan. 5, we will swear in the National Assembly and preserve that sovereignty as the Venezuelan people and international observers look on."

The opposition won a landslide victory earlier this month, taking control of congress for the first time in more than a decade. The coalition captured 112 of 167 seats, giving it a crucial two-thirds majority by one seat. That super-majority would allow government critics to censure top officials and could open the door to recalling Maduro or even rewriting the constitution.

Opposition coalition spokesman Jesus Torrealba released an open letter Wednesday asking international bodies including the United Nations and the European Union to help stop the government from stealing back control of the legislature.

"The country, the region and the world face a judicial coup d'état attempt against the decision the Venezuelan people made at the ballot box," he wrote.

The ruling has not provoked popular unrest in the middle of weeks-long winter vacations. In Caracas, the streets were unusually empty, save for groups of people launching fireworks and drinking rum in anticipation of the new year.

But Tuesday's swearing in ceremony could be a tinderbox. Government supporters have promised to rally outside the National Assembly, and the opposition is calling for government critics to join all 112 elected deputies in a march to the building.

The hardline members of the opposition who led a wave of bloody 2014 street protests are calling for a show of force.

"The best response to this moribund regime is to show in the streets how many of us there are on Jan. 5," opposition leader Freddy Guevara said.