Poland's pro-EU opposition has a 10-point lead over the ruling nationalists ahead of European Parliament elections, a survey showed on Friday, a sharp turnaround that some analysts linked to a film about sexual abuse scandals in the Catholic Church.

The documentary Just Don't Tell Anyone, which shows victims of child abuse confronting priests who had sexually abused them, has shocked Poles.

The powerful Catholic Church has close ties with the governing Law and Justice party (PiS).

The European Coalition, which comprises pro-Europeans from across the political spectrum, would win 43.6 per cent and PiS 32.9 per cent in the May 26 election, according to the poll, conducted on May 14-16 by the Institute for Research into Public Affairs (IBSP) for Newsweek and Radio Zet.

Most previous opinion polls have put PiS, which takes a conservative stance on social and moral issues while favouring a bigger state role in the economy, in the lead for both the EU election and for a national election due later in 2019.

The drop in support for PiS ahead of the EU elections is linked to the strong emotions stirred up by the documentary, said Lukasz Pawlowski from the Polish Nationwide Research Group, to which IBSP belongs.