A senior aide said yesterday he was standing by Poland's conservative opposition leader Jaroslaw Kaczynski, reeling after losing his presidential twin and a swathe of party stalwarts in an air crash.

"I am spending a lot of time with Jaroslaw Kaczynski, so that he isn't alone for too long," Adam Bielan, spokesman for the Law and Justice party and a close aide to Kaczynski, said on Polish radio.

Experts said that the death of a twin is always traumatic and the deep personal and political bonds with his late brother Lech would add an extra edge for the unmarried Jaroslaw, 60. In public, Kaczynski has displayed little emotion, even after identifying his brother's body hours after the crash. He sank to one knee and bowed his head when the president's coffin returned to Warsaw on Sunday but shed no tears.

Adding to the psychological blow, the Kaczynskis' mother, 84-year-old Jadwiga, has been in hospital for the past month in critical condition.

In addition to Lech Kaczynski and his wife Maria, Saturday's crash in Smolensk in western Russia claimed the lives of 94 others including leading politicians, the head of Poland's central bank, and the military's top brass.

Among the dead were eight senior figures from Law and Justice, a party created by the identical Kaczynski twins.

Jaroslaw Kaczynski had initially been scheduled to be on the Polish official plane which was bound for a World War II memorial ceremony, but was replaced by Law and Justice kingpin Zbigniew Wassermann.

Speculation has already begun that Kaczynski would be the conservatives' natural candidate to replace his late brother, but the aide said Kaczynski was not thinking about the issue.

"Jaroslaw Kaczynski doesn't have politics on his mind right now," Bielan said. "He has lost his brother and many friends".