Miller says the affair is being used to discredit him

Appearing before a parliamentary commission for a second day, Mr Miller reiterated that he had played no part in an alleged attempt to solicit a bribe from a top newspaper.

And he accused the opposition of exploiting the affair for political gain.

The affair has been used for political reasons to discredit me and my party Leszek Miller

The case centres on allegations that a film producer tried to get money from the editor in chief of the newspaper, Gazeta Wyborcza, saying he could influence forthcoming government legislation on media ownership in the newspaper's favour.

Mr Miller has been accused of not approaching prosecutors to tell them what he knew about the scandal.

On Saturday he said he said he had not taken the affair seriously because "the whole thing seemed absurd".

On Monday he added that he had attempted to clarify the matter by holding talks with the Justice Minister and the head of the Internal Security Agency.

He also rounded on political opponents.

"The affair has been used for political reasons to discredit me and my party," he said in response to questioning by a bitter adversary, rightist MP Zbigniew Ziobro.

'Rywingate'

He added: "I am convinced that no law can be bought from the Polish parliament."

At the heart of the case is the allegation that film producer Lew Rywin tried to obtain a bribe of $17.5m from Gazeta Wyborcza's chief editor, Adam Michnik.

He is alleged to have offered to guarantee, in return, that a new law on media ownership would not prevent the newspaper's proprietors from realising their ambition to acquire a TV station.

Mr Michnik refused, but waited almost six months to publish the story, saying this was to protect Poland's negotiations to join the European Union.

Mr Rywin is the owner of the production company Heritage Films, which co-produced the Holocaust epics Schindler's List and The Pianist - the Roman Polanski film which won the Golden Palm in Cannes last year and Hollywood Oscars for best director, best actor and best screenplay.

EU supporters are hoping turnout will not fall below 50%

Mr Miller told the commission on Saturday he regarded himself as a "victim" of the so-called Rywingate affair.

He said that, as somebody who had been defamed and wronged by the allegations, he was himself deeply interested in obtaining an explanation.

On Monday the Polish press widely covered Saturday's hearing.

"The premiere of the premier," was the comment of the left-leaning Trybuna.

There have been no new revelations which might damage Mr Miller's minority government or shake financial markets.

But the BBC's Nicholas Walton in Warsaw says says the scandal has disillusioned many Poles, reinforcing their belief that Poland suffers from high levels of corruption.

He says the case is bad news for those worried about low turnout in June's EU referendum.

If less than 50% of voters go to the polls, membership would have to be ratified by a two-thirds majority in the Polish parliament.