Poland's President Lech Kaczynski yesterday appointed his identical twin brother, Jaroslaw Kaczynski, as the new prime minister.

The president "appointed Jaroslaw Kaczynski as the president of the Council of Ministers," the presidential website said, using the formal term for prime minister.

Earlier, Prime Minister Kazimierz Marcinkiewicz and his government formally resigned, clearing the way for Jaroslaw Kaczynski to form a new government.

Marcinkiewicz resigned in a meeting with President Lech Kaczynski two days after the governing Law and Justice party decided to replace him with Jaroslaw Kaczynski, the party chairman.

"I thanked him for his very good governing," Lech Kaczynski said in a brief statement after a 45-minute meet-ing with Marcinkiewicz at the presidential palace.

Marcinkiewicz departed amid reports of disagreements between him and Jaroslaw Kaczynski, who was widely regarded as the power behind the scenes of the outgoing government. The rift had reportedly widened recently over conflicting views of Poland's economic policy.

While Marcinkiewicz is leaving his post, most of his ministers are expected to stay in the new government under Jaroslaw Kaczynski.

Kaczynski has said his future Cabinet would continue the pro-social welfare policies of Marcinkiewicz's government and that Kaczynski said at a news conference that new Finance Minister Stanislaw Kluza would continue the policies of his predecessor, Zyta Gilowska, who - until she resigned two weeks ago - was seen as the key guarantor of fiscal responsibility in Poland's government.

Marcinkiewicz will now run as the Law and Justice party's candidate for mayor of Warsaw in autumn elections.