The Supreme Court in Venezuela has barred four incoming lawmakers from taking office, effectively blocking the two-thirds majority that the opposition won in recent legislative elections.
The decision came on Wednesday in response to a legal challenge filed by supporters of the ruling United Socialist Party of Venezuela against vote irregularities.
The ruling affects three opposition MPs and one socialist lawmaker, all from the state of Amazonas, as the suit challenges the vote for the entire state.
It blocks the legislators from taking their seats when the new National Assembly convenes on January 5.
The opposition won a victory in the December 6 polls, taking control of congress for the first time in over a decade.
The coalition secured 112 of 167 seats, giving it by one seat a two-thirds majority that would allow it to restrict the powers of President Nicolas Maduro and even to rewrite the constitution.
In reaction to the Wednesday ruling, opposition leaders charged the government with using institutions to overturn the will of the people.
The court must now examine arguments in the case, for which there is no fixed time. If it finds that the polls were fraudulent, they will have to be held again in the areas involved.