Opposition party leaders have reached coalition agreement

The pro-EU alliance spans the political spectrum with parties differing on issues from public spending to abortion. But their leaders say they are united by a desire to improve relations with Brussels and unblock funds for Poland frozen due to a rule-of-law dispute with the bloc.

"We are ready to take responsibility for Poland in the coming years," Tusk told a news conference.

In a document the parties made a series of pledges, including restoring transparency to the public finances and depoliticising state-owned companies.

The agreement also said that the coalition would overturn a Constitutional Tribunal ruling from 2020 that resulted in a near-total ban on abortion.

The issue of abortion is a sensitive one in an alliance that includes both Catholic social conservatives and left-wingers.

"Everything cannot be reduced to one denominator," said Władyslaw Kosiniak-Kamysz, leader of the centre-right Polish Peasants' Party (PSL), which contested the election as part of a coalition called Third Way.

"In our agreement, we found a common denominator for the issues we want to implement. They concern: support for families, employees, entrepreneurs, the Polish countryside, education, health care and women's rights."

According to the agreement Kosiniak-Kamysz will serve as deputy prime minister, as will Krzysztof Gawkowski from the New Left.

The role of parliament speaker will be shared between Third Way's Szymon Holownia and the New left's Włodzimierz Czarzasty with each taking up the role for two years.

President Andrzej Duda has given the ruling nationalist Law and Justice (PiS) party the first shot at forming a government. But PiS lacks a majority and with all other parties having ruled out working with it, its task appears almost impossible.

If Prime Minister Mateusz Morawiecki is unable to win a vote of confidence, parliament will appoint another government.