By Anna Koper and Joanna Plucinska
WARSAW (Reuters) - Polish presidential challenger Rafal Trzaskowski tried to rally supporters of other opposition candidates to his centrist cause on Monday, vowing to hold the nationalist government to account ahead of what looks set to be a knife-edge run-off vote.
Incumbent president Andrzej Duda, an ally of the ruling Law and Justice (PiS) party, led the first round of the presidential election on Sunday, but fell short of the 50% needed for outright victory, setting the stage for a run-off with Trzaskowski on July 12.
"I am directing my words to all those who want change," Trzaskowski, the liberal mayor of Warsaw, told supporters in the city of Plock.
"Without them, there will be several more years of a monopoly on power which is not honest and cannot be held to account because it attacks independent institutions."
PiS badly needs Duda to be re-elected if it is to further its socially conservative agenda, including judicial reforms which the European Union says undermine the rule of law.
Duda has painted himself as the guardian of the government's social benefit programmes and conservative social values, which mirror those of the powerful Catholic Church.
The morning after the election, Duda said he would ensure that gay couples could not adopt children, in an appeal to the almost 7% who voted for far-right candidate Krzysztof Bosak.
"We want the family to be respected in Poland," Duda told Polish public radio. "We want traditional values to be a strong backbone that Polish society will lean on."
The Parliamentary Assembly of the Council of Europe (PACE), observing an election in Poland for the first time since 1991 due to concerns about the rule of law, and the Office for Democratic Institutions and Human Rights (ODIHR) both said voting had been well organised.
However, both pointed to inflammatory language during the campaign and a lack of impartiality from the public broadcaster TVP.
They also criticised the haste with which changes allowing large-scale postal voting for the first time were passed.
The changes were designed to enable voters to avoid attending polling stations during the coronavirus pandemic, and to facilitate voting by Poles abroad.
But many Poles living abroad say they did not receive their ballot papers.
Anna Trzop, a 34-year-old lawyer working in Brussels, said she was worried that she would not receive her voting package before the second round.
"Looking at the polls, those few thousand votes could make the difference," she said.
Two opinion polls conducted late on Sunday for TVP and the private broadcaster TVN gave Duda, who received 44% of first-round votes, a lead of less than two percentage points for the run-off.
Trzaskowski, standing for the largest opposition party, the centrist Civic Platform (PO), came second with 30%.
(Reporting by Joanna Plucinska, Anna Koper and Pawel Florkiewicz; Writing by Alan Charlish; Editing by Justyna Pawlak and Alison Williams)