The funeral of Kaczynski and his wife will take place on Sunday in the cathedral of Krakow's historic Wawel castle. World leaders including US President Barack Obama and Russian President Dmitry Medvedev are to attend, Agence France-Presse (AFP) reported on April 14.

But opposition mounted to plans to bury the conservative president in a spot where Polish kings and historical figures are laid to rest, with protesters taking to the streets and more than 34,000 joining a Facebook campaign.

"President Lech Kaczynski was an ordinary and good man, but there is no reason for him to lie in the Wawel among the kings of Poland and Marshal Jozef Pilsudski," the founding father of modern-day Poland, acclaimed film director Andrzej Wajda wrote in an open letter published on the website of the liberal daily Gazeta Wyborcza.

The early ballot for Kaczynski's successor after he and 95 other people were killed in a plane crash in western Russia at the weekend will be held on June 13 or 20, said parliamentary chancellery chief Lech Czapla.

Interim president Bronislaw Komorowski said after meeting MPs that the final date would not be announced until April 21, three days after Kaczynski's state funeral in Krakow, indicating a June 20 snap election.

Thousands of people queued through the night to pay their respects to Kaczynski, 60, and Maria, 66, as their bodies lay in state for a second day at the presidential palace in central Warsaw. The line stretched for more than a kilometre (around half a mile) and families with children waited in the cold for up to 10 hours before filing silently past the closed coffins, which were draped with red and white Polish flags.

"I came from Lodz at nine this morning and have been in line for four hours -- I expect I'll be in the palace by seven this evening," said Benedict Wardachowicz, 60.
Poland extended the mourning period by one day until Sunday for the victims of the crash, many of them top military and political figures, which happened as the jet taking them to a memorial for a World War II massacre tried to land.

A plane carrying the bodies of 30 more victims arrived home from Moscow on Wednesday. A sport s arena has been set up for their coffins so relatives can pay their last respects.
But in a rare breach of the unity seen in Poland since the crash, several hundred people gathered in Krakow late Tuesday crying "Not in the Wawel" and waving banners marked "Is he fit to be a king?"

Further protests were planned late Wednesday.The nationalist Kaczynski, in office since 2005, was a divisive figure at home and abroad, but the mood since his death has been one of unity in grief.

Under the Polish constitution Komorowski, who is also the parliament speaker, must call the election within two weeks of the president's death and the ballot must be held within 60 days of the announcement.

Komorowski, a liberal, had been expected to run against Kaczynski in the October election. Kaczynski's identical twin brother Jaroslaw, who was premier from 2006-7, may take his sibling's place. He has made no public statement since the crash.
The announcement by the Kremlin that Medvedev would also be at the funeral was a further sign of warming relations between Moscow and Warsaw.

Bad blood between the two countries has been fuelled over the years by disagreements such as the one over the Katyn massacre, in which Soviet secret police slaughtered thousands of top Polish officers in 1940.

Kaczynski's delegation had been on its way to commemorate the 70th anniversary of the massacre when the presidential jet crashed.Russian investigators have pointed to pilot error. Air traffic controllers say the crew refused three times to heed advice to divert to another airport because of the fog.