Czech Prime Minister Petr Necas was clinging to office on Friday after prosecutors accused his personal assistant of being at the centre of a corrupt web of political favours and secret surveillance.
Police raids on government offices on Thursday signalled the most significant action against corruption in two decades in a country that has been mired in sleaze since its "Velvet Revolution" overthrew Communism in 1989.
The main Czech opposition party said it would initiate a parliamentary vote of no confidence unless Necas quits, but in a defiant speech to lawmakers, the conservative prime minister dismissed the allegations and said he would stay on. His fate now depends on whether the smaller parties in his coalition stand by him, and on whether President Milos Zeman, a political opponent, tries to use his limited constitutional powers to push Necas out.
Jeronym Tejc, an official of the opposition Social Democrat party, said: "(We) expect the speedy resignation of Prime Minister Petr Necas and the entire government. If that does not happen, the Social Democrats will initiate a vote of no confidence."
A day earlier hundreds of police with the organised crime unit, some in balaclavas to conceal their identity, swept through the government headquarters, the defence ministry, a bank and private homes, detaining several Necas associates.
Police said they confiscated czech currency worth at least $6 million in the raids, as well as tens of kilograms of gold. Necas was drawn even deeper into the affair on Friday when prosecutors, giving details of their investigation for the first time, alleged the existence of corrupt dealings that intersected with Necas's personal and political life.
Tomas Sokol, a lawyer for one of the people charged, the former head of military intelligence, said prosecutors had accused his client of instructing agents to run surveillance on Necas's wife, Radka. Necas and his wife, his college sweetheart, announced this week they were divorcing.
Corruption was rife under communism but it has grown exponentially in many eastern European countries since they made the transition to a market economy. Graft is a part of everyday life in much of the region, but convictions are rare.
The Czech investigation was unusual because of its scale, and the ambition of taking on a political establishment which previously seemed to be immune from prosecution.
Prosecutors have charged seven people, including the head of Necas's office, two military intelligence service members, and two former members of parliament, high state attorney Ivo Istvan told a news conference.
They said their suspicions focused on two areas: allegations that officials used the intelligence services for inappropriate purposes, and that corrupt favours were given to politicians.
The prosecutors said the common factor in both sets of allegations was Jana Nagyova, who heads Necas's office. She has worked for Necas since 2006. Elegantly dressed and with blonde, shoulder-length hair, she has often appeared in Czech tabloids. "In both of these two criminal cases, one person appears," said Pavel Komar, one of the prosecutors handling the case. "The case of Ms Nagyova has to do with organising criminal activity through the abuse of power and bribery."
A government spokesman refused to comment on the charges against Nagyova, who was born in 1965, and it was not immediately possibly to identify a lawyer who is representing her. Necas said on Thursday he did not believe she did anything dishonest.