Jaroslaw Kaczynski, the late Polish president's twin brother, leads acting president Bronislaw Komorowski ahead of the presidential runoff on July 4, an opinion poll released on Thursday said, RIA Novosti reported.
The GfK Polonia research agency poll indicated that some 49% of voters supported Kaczynski, with 47% for Komorowski.
Komorowski, a pro-EU, moderate member of the governing Civic Platform party, was made acting president after a host of senior Polish officials including President Lech Kaczynski died in a plane crash in western Russia in April.
Jaroslaw Kaczynski, who leads the conservative Law and Justice party, received 36.46% during the first round of voting. Komorowski gained 41.54%.