WARSAW (Reuters) - A new progressive party in Poland run by an openly gay politician has vaulted into third place in a public opinion poll, potentially complicating the ruling conservatives’ prospects for winning a parliamentary election later this year.

FILE PHOTO: Robert Biedron, pro-European and openly-gay mayor of Polish city of Slupsk during the launch of his new political movement 'Wiosna' in Warsaw, Poland February 3, 2019. Slawomir Kaminski/Agencja Gazeta/via REUTERS/File Photo

A former mayor of the northern city of Slupsk, Robert Biedron, 42, presented his new “Spring” party on Sunday, with a program that includes liberalizing Poland’s strict abortion laws, phasing out coal by 2035 and taxing the powerful Catholic Church.

A survey published late on Tuesday by private broadcaster TVN, the first since the party’s launch, showed its support at 14 percent. The ruling Law and Justice (PiS) party stood at 29 percent, one percentage point lower than in January.

The main centrist opposition grouping, which consists of the Civic Platform of European Council President Donald Tusk and a smaller pro-business party, saw its support slip five percentage points to 20 percent, the poll by Kantar Millward Brown showed.

One of Europe’s biggest eurosceptic parties in power, PiS has welcomed the rising popularity of Biedron, a former gay rights activist, as having the potential to further fragment the opposition in Poland.

But the emergence of Spring, with its strongly pro-EU platform, could become a threat to PiS rule if it galvanizes voters outside the traditional centrist electorate who are angry over the government’s mounting conflict with the European Union.

“It’s true that Biedron’s party eats into the (centrist’) support,” said Anna Materska-Sosnowska, a political scientist at the University of Warsaw. “PiS would worry more if the youth and those who don’t vote become mobilized.”

Poland, which is holding parliamentary elections in the autumn, has one of the lowest voter turnout rates in Europe, largely due to its partisan politics and a legacy of distrust in state institutions following decades of communist rule.

PiS, which has been in power since late 2015, argues it has tried to improve the functioning of the state by overhauling the justice system and public media, but critics at home and abroad accuse it of an authoritarian power grab. The government faces unprecedented legal action from Brussels over its adherence to EU rule of law standards.

Biedron has said that, if elected, he would establish a Truth and Reconciliation Commission, styled after a body set up in South Africa after apartheid ended, in an effort to examine any abuse of power by the PiS government.

“We will hold those who have subverted basic rights and freedoms accountable,” he told supporters on Sunday, according to the state PAP news agency.

In recent months, PiS has also battled a series of scandals, with local media accusing the party of allowing excessive pay at the central bank and running a murky real estate business, as well as corruption at the financial market regulatory authority.

PiS denies any wrongdoing.

Its popularity ratings have edged down slightly since late last year, but it remains the most popular party in Poland amid robust economic growth, low unemployment and voter support for its calls for more conservative values in public life.