PARIS -- The Czech Republic's governing party began jockeying to form a new government on Monday after the prime minister, Petr Necas, resigned over an espionage and bribery scandal that has plunged the country into political instability.
His resignation came just days after an organized crime unit began the most extensive anti-corruption operation since the end of Communist rule in 1989.
In nationwide raids, officers wearing black face masks arrested several officials with links to Mr. Necas, and seized $8 million in cash, tranches of documents and quantities of gold.
Mr. Necas had come under pressure to resign after his chief of staff, Jana Nagyova, was charged Friday with abuse of power and bribery. Prosecutors and the police said she had ordered the intelligence services to spy on three people, including Mr. Necas's wife, whom he is divorcing. The police said they were shocked when wiretaps of Ms. Nagyova's phone showed that she had used the secret services for personal motives.
Ms. Nagyova's lawyer denied the allegations to the Czech news media.
The current and former heads of military intelligence, two former members of Parliament from Mr. Necas's center-right Civic Democratic Party and a former minister were also arrested.
Law enforcement officials said Ms. Nagyova, a close confidante of Mr. Necas, was also suspected of bribing the three former members of Parliament with offers of posts in state-owned firms, in return for them giving up their seats. The three had been rebelling against a government austerity package.
Mr. Necas said he had done nothing wrong and vehemently denied having any knowledge of the illegal surveillance operation. On Monday, he said he was leaving politics and would not seek re-election.
At a news conference on Sunday, he indicated that the ensnaring of a close aide in the scandal had made it untenable for him to remain in his post. "I am fully aware how the twists and turns of my personal life are burdening the Czech political scene and the Civic Democratic Party," he told reporters in Prague, the Czech capital.
Following his resignation, the departing coalition could try to form a new government led by a new prime minister who could remain in office until elections scheduled for June 2014.
Martin Kuba, 40, the trade and industry minister and the deputy chairman of the Civic Democrats, has been mentioned by the Czech news media as a leading candidate for the prime minister post. Mr. Kuba, a doctor and former owner of a bakery franchise, has close ties to the corporate sector.
President Milos Zeman, who has the power to appoint the prime minister under the Constitution, is a strong-willed rival of Mr. Necas, and could decide to choose his own candidate to head a caretaker government. If he fails to find a candidate who gains the confidence of Parliament after three attempts, early elections would be triggered.
The opposition Social Democratic Party, which had threatened a no-confidence vote on Tuesday unless Mr. Necas resigned, called on Monday for early elections, saying that it would not back the coalition remaining in power, even under a new prime minister.
Jiri Pehe, the director of New York University in Prague, said that while the country was in for a period of political instability, Czechs were used to living in a state of political crisis and that it was unlikely to paralyze the country or undermine economic policy.
While the Czech Republic has slumped into a modest recession since 2011, tough austerity measures by the departing government had kept debt levels manageable, and the country's banking sector is stable.
"For more than a decade Czech politics has been in crisis mode, with governments falling or on verge of collapsing, and yet the country has done pretty well," Mr. Pehe said. "This crisis could have a positive effect on the fight against corruption, as it has served as a warning to the country's godfathers and big crooks that they can no longer feel safe."
This article originally appeared in The New York Times.