Venezuelan officials from the ruling socialist party are gearing up to launch a criminal investigation against another opposition figure, just days after the high-profile arrest of the mayor of the capital Caracas sparked fears of a larger political crackdown.

Legislators from President Nicolas Maduro’s United Socialist Party of Venezuala are expected to vote Tuesday to open a preliminary investigation of Julio Borges, a deputy from the opposition party Primero Justicia (Justice First) and a longtime critic of Maduro, over allegations that he worked with other high-profile opposition figures to foment a government overthrow.

A leader of the socialist party said that Tuesday’s National Assembly meeting could result in Borges being stripped of his parliamentary immunity before ultimately facing prison, according to news agency Efe. Several socialist party officials have maintained that there is ample evidence against Borges to justify the investigation, but they haven’t detailed them.  

Lawmakers had been discussing the possibility of investigating Borges for several days, following President Maduro’s Feb. 12 announcement that the government foiled an alleged coup plot against his administration. Federal agents arrested Caracas Mayor Antonio Ledezma, a well-known critic of the Maduro government, last week for his alleged involvement in the scheme, stoking suspicions that the administration was taking more aggressive measures on members of the political opposition. Borges’ impending investigation has further fueled those suspicions.

The coup plot, Maduro said, involved a collusion between members of the air force and the political opposition, with U.S. backing, to attack the presidential palace with a military plane. In addition to Borges and Ledezma, top government officials also named Maria Corina Machado, a former lawmaker who was expelled from the national assembly and charged in separate conspiracy accusations last year, and Leopoldo Lopez, an opposition leader who has been imprisoned for more than a year for his role in the February 2014 mass antigovernment protests, as co-conspirators.

The Maduro administration has pointed to a document outlining political transition plans signed by Machado, Lopez and Ledemza as evidence that the three were planning a government overthrow. Borges, officials said, was a key participant in meetings the opposition held with military officers to plot the attack. But government critics say Maduro has not produced any solid evidence to back up his claims of a coup plan.

The U.S. State Department rejected accusations that it was behind any plan to destabilize the government. Meanwhile, members of Venezuela’s opposition have appealed to the Organization of American States, the regional organization in charge of mediating disputes, to address Venezuela’s human rights situation in light of Ledezma’s arrest, saying the government's moves against the opposition deviated from democratic principles.