Poland's conservative opposition party PiS leads opinion poll

WARSAW (Reuters) - Poland's main opposition party, the conservative Law and Justice (PiS), is the most popular among voters, with the ruling Civic Platform (PO) five percentage points behind, a poll by TNS Polska showed on Sunday.

Support for PiS rose two percentage points to 31 percent, while PO's reading remained unchanged at 26 percent, according to the poll conducted for public television TVP.

Poland does not have a national election until late 2015, but this year Poles will vote in European Parliament elections and local elections.

Flagging ratings for Prime Minister Donald Tusk have been causing discord within his own party. That, say analysts, may increase pressure on Tusk to adopt voter-friendly measures that could hurt market confidence.

(Reporting by Adrian Krajewski)