Warsaw  - Poland's sports minister and the head of the ruling Civic Platform party lobbied on behalf of gambling companies to block a change in law that would have required gambling companies to pay 469 million zloty (162 million dollars) in additional taxes, the daily Rzeczpospolita reported Thursday.

The Central Anti-Corruption Bureau (CBA) found that businessmen Ryszard Sobiesiak and Jan Kosek, owners of the Casinos Poland chain, pressured Zbigniew Chlebowski, the head of Civic Platform, and Sports Minister Miroslaw Drzewiecki to remove a provision requiring additional taxes from an amendment to the country's gambling law.

Prime Minister Donald Tusk said Thursday he proposed that Chlebowski step down as party head until the matter was "cleared up."

Tusk said he found no evidence that a crime had been committed when he met in August with CBA about the investigation. He said his intention was for CBA and prosecutors to resolve the matter.

The additional taxes would have gone to help Poland prepare to host the Euro 2012 football championship.

Chlebowski defended himself to reporters in Warsaw on Thursday, while Justice Minister Andrzej Czuma said there was not enough evidence of Chlebowski's or Drzewiecki's guilt.

The CBA warned the president, prime minister and parliament that the government budget could lose 469 million zloty if the changed amendment sought by lobbyists became law, Rzeczpospolita said.

CBA launched an operation code-named "Black Jack" on March 23 and tapped the phone lines of both businessmen to determine whether they were in regular contact with Drzewiecki and Chlebowski.

Chlebowski was targeted because he heads a commission on public finances that was to vote on the draft gambling bill, the daily said. Drzewiecki is in charge of readying Poland to host the Euro 2012 championship.

"It can't be that private conversations should be the basis of far-reaching accusations," Chlebowski told reporters in Warsaw. "This is a bill that was changed because of many social consultations," he said, adding that the bill contained no "injustices."

But Jaroslaw Kaczynski, head of the opposition Law and Justice party, called it the "biggest scandal" in recent Polish politics during a press conference in Warsaw.

The Democratic Left Alliance called for the dismissal of both politicians.

Drzewiecki in May 2009 wrote to the vice-minister of finance that additional taxes from gambling companies were not needed because of changes in Euro 2012 investment plans. The provision for the additional taxes was removed from the draft bill.  dpa