Wladyslaw Stasiak, the head of the National Security Council, has been sworn in as the new interior minister, reports AP.

The latest developments come after Andrzei Lepper, leader of junior government coalition partner the Self Defence Party, pulled his ministers out of government on Sunday.

Mr Lepper was last month also fired from his post as deputy prime minister and farm minister by the prime minister after being accused of being involved in the same corruption scandal.

The scandal involves allegations that bribes were paid to get agricultural land rezoned.

Poland's anti-corruption agency says that Mr Lepper was tipped off that the agency was looking into suspected corruption at his ministry, and has been looking for the source of the leak.

Mr Lepper has denied the accusations levelled against him.

Self Defence's withdrawal from government means the ruling Law and Justice Party cannot get a majority.

Some 231 votes are needed for a majority, while the Law and Justice Party only accounts for 155. The League of Polish Families, the third member of the coalition, only has 34 MPs.

The crisis has prompted speculation that there will soon be early elections in the country. Officially the next election is due in 2009.

Mr Kaczynski has said he is in favour of early elections.

"I am in favour of prompt elections because we face a destructive opposition... There is no point in prolonging things for a long time," he said, according to the BBC.