A former minister has been detained by Poland's Kaczynski government, a move the opposition says is designed to silence critics in the lead up to an expected early election. Prosecutors detained on Thursday (August 30) Poland's recently fired interior minister, who has accused Polish Prime Minister Jaroslaw Kaczynski of using secret services to spy on rival politicians. The prosecutor service said Janusz Kaczmarek was hampering an investigation into a corruption case. The opposition said Kaczynski was trying to muzzle critics ahead of an expected snap election. "I don't know anything more than you, but I am extremely surprised about the manner in which Mr. Kaczmarek was brought to be questioned," Kaczmarek's attorney Wojciech Brochwicz told reporters. "Since he returned to Poland he was not hiding, he was at the disposal of the parliament, the police and the media. He could have been summoned at any moment to be questioned; he surely would have come on his own. There were no reasons to assume otherwise," Brochwicz added. The opposition said Kaczynski was trying to cover up abuses of power ahead of a parliamentary vote next week on calling the snap poll two years ahead of schedule. Opinion polls show that despite a booming economy and falling unemployment, Kaczynskis' Law and Justice (PiS) party faces an uphill battle to remain in power. Its rule has been marked by conflicts inside the cabinet and rows with EU partners. The opposition and human rights groups say the government's anti-corruption drive has turned into a witch-hunt in which anyone who does not share the ruling party's views is branded a criminal or a traitor to Polish interests. Such accusations gained ground when Kaczmarek testified in parliament last week that the secret services were spying on a number of opposition and government politicians. "I have to say that I will not give up. I will definitely fight and I will not be intimidated. I will not give anyone the satisfaction of making me the second Barbara Blida," Kaczmarek had said, referring to a left-wing politician who committed suicide upon her arrest by the ABW in April this year. "I will speak loudly about my knowledge, about the acts of misconduct known to me. Today the prosecutor's office and the secret services are tools in the hands of the ruling class. Today everything that was meant to be good, that was meant to serve truth, law and justice is being used to hold power. They begin trials against politicians and hold them up. Because the prosecutors are only interested in politicians now," Kaczmarek added. Kaczynski has called the accusations groundless and accused the opposition of spreading chaos by demanding a parliamentary inquiry into the affair. "The recent developments which are so shocking for the public and the opposition are the result of a normal functioning of the justice system. There are no grounds to look for any other meaning," Kaczynski told reporters. Since the break-up of Kaczynski's three-party coalition earlier this month, Law and Justice has no majority in parliament. Parliament next meets on September 4 and is due to vote on dissolving itself to pave way to snap polls. The leftist opposition said elections would be premature in the current climate and urged other opposition parties to join forces to remove Kaczynski through a vote of no-confidence.