Polish opposition party leader Jaroslaw Kaczysnki has blamed Russia and the Polish government for the plane crash that killed his brother and 95 others last year.
A plane crash in Russia last April killed President Lech Kaczynski and many prominent political and military leaders.
Recriminations have reached a fever pitch since a Russian aviation commission declared this month that blame for the crash rests fully with the Poles.
The Polish government believes most of the blame rests with the Polish pilots, but that Russian air traffic controllers also made errors.
Kaczynski on Saturday called the Russian explanations a "gigantic scandal" and said Russians are to blame.