Spain's parliament will debate a no-confidence motion against Prime Minister Mariano Rajoy's government on Thursday and Friday.
"The speaker of the parliament announces that the debate on the no-confidence motion... will take place on May 31 and June 1," a Twitter message issued by parliament said.
The vote on the motion, which was called by the main opposition Socialist party, should take place at the end of the debate on Friday but it could be put off to Saturday, a parliament press office official told AFP.
The Socialists filed the motion seeking Rajoy's ouster in parliament on Friday, a day after a court fined his Popular Party for benefiting from illegal funds in a massive graft trial.
Spain's National Court said Thursday it had uncovered a vast system of bribes given to former PP officials in exchange for lucrative public contracts between 1999 and 2005.
It sentenced 29 people to jail for a total of 351 years for corruption, embezzlement and money laundering in the so-called Gurtel trial.
The PP itself was not on trial for direct involvement in the scheme but was found to have benefited from funds obtained illegally through "an authentic and efficient system of institutional corruption" including a slush fund. It was ordered to pay back 245,000 euros ($290,000).
"The question that will arise, Thursday or Friday, is whether to vote for or against the government. Cooperate or not with impunity. That is the question," a top Socialist party official, Jose Luis Abalos, said Monday.
The Socialists can already count on the support of anti-establishment Podemos but would need to convince Catalan separatists and Basque nationalists -- or the liberal Ciudadanos party -- to obtain a majority in the 350-seat parliament for the no-confidence motion.
Rajoy's allies Ciudadanos, who have overtaken the PP in some recent polls thanks to a hard line on Catalan separatism, immediately said it would oppose the no-confidence motion and instead called for snap polls.