Spanish Prime Minister Mariano Rajoy will face a vote of confidence in his leadership on Friday as corruption convictions handed down to dozens of people linked to his center-right People’s Party (PP) threatened his six-year rule.

Spain’s parliament agreed on Monday that the debate and vote would take place on Thursday and Friday, although the opposition Socialists who proposed the vote may struggle to garner enough support in the fragmented legislature to unseat Rajoy.

Opposition parties are taking advantage of Rajoy’s weakness after 29 people linked to the PP were convicted last Thursday of crimes including influence-peddling and falsifying accounts, in the culmination of a long-running corruption trial.

The PP has closed ranks behind Rajoy, who said on Friday he intended to serve out his four-year term and that the corruption convictions did not affect a single member of his government. The 63-year-old survived a no-confidence vote last June.

Ciudadanos (Citizens), a liberal party ahead in opinion surveys and the most likely to win a snap election, urged Rajoy on Monday to call an early poll.

Rajoy’s government is weak and tainted by the corruption convictions, Ciudadanos leader Albert Rivera said in an interview with El Mundo newspaper.

“The only democratic and dignified way out is to give voice to the Spanish people so that they choose a new government and parliament,” he said.

Ciudadanos said on Saturday it would be willing to work with the Socialists to support a neutral candidate to oust Rajoy, whose minority government has been damaged by a crisis sparked by a Catalan independence vote.

However, it is not clear whether the Socialists and Ciudadanos will team up to topple the Rajoy government.