WARSAW (Reuters) - Support for Poland’s governing party has fallen, a survey published late on Tuesday showed, as it scrambles to contain fallout from the country’s biggest corruption scandal in years.

Support for the Law and Justice (PiS) party fell by five percentage points to 33 percent in the Kantar Millard Brown poll, compiled this week. It rose for the opposition Civic Platform by the same amount to 26 percent, private broadcaster TVN said.

Financial regulator Marek Chrzanowski quit last week over corruption allegations by Polish billionaire Leszek Czarnecki, who controls two troubled banks, Getin Noble Bank and Idea Bank.

Czarnecki alleged that Chrzanowski asked him to hire a specific lawyer and pay him 40 million zloty ($10.58 million) in exchange for the regulator’s “support” for Getin Noble Bank.

Chrzanowski denies any wrongdoing. He was appointed by the PiS.

Opposition groups have called for a parliamentary inquiry into the scandal, which PiS has rejected. The opposition questions whether CBA, Poland’s anti-corruption agency, should investigate the case. Fifty-eight percent of Poles want an independent investigation, according to the Kantar poll.

The CBA’s role is being questioned after the newspaper Gazeta Wyborcza reported that the son of Mariusz Kaminski, the head of CBA, was hired by the World Bank in July thanks to support from the Polish central bank.

Kaminski says he has not spoken to the governor of the central bank concerning his son’s job. The central bank confirmed his statement, according to the state news agency PAP.

PiS party head Jaroslaw Kaczynski was not aware of the younger Kaminski’s job and the issue would be checked, a party spokeswoman said on Wednesday.

Shares in Getin Noble have fallen by more than 87 percent and Idea Bank by 92 percent this year on the worries about their stability. Polish bonds prices and the zloty also fell last week on the scandal.

The central bank committed at the weekend to offer liquidity as concern grew among customers of Czarnecki’s banks. The central bank also reminded customers that deposits are guaranteed up to 100,000 euros ($113,930.00).

By 1005 GMT on Wednesday, Getin Noble shares had reversed early loses and risen 14 percent. Idea’s rose 11 percent.

Jacek Sasin, a senior aide in the prime minister’s office, dismissed speculation that the PiS might call a snap election.

“Nothing has happened to discuss this at all,” he told private Radio Zet on Wednesday.