WARSAW, July 3 (Reuters) - Former European Council President Donald Tusk returned to the fore of Polish politics on Saturday, becoming leader of the main opposition party in a move that many members hope can revive its sagging fortunes.
For many in the liberal Civic Platform (PO) party that Tusk helped to found, the stakes are nothing less than Poland's future in the European Union.
Elections scheduled for 2023 will determine if the governing nationalist Law and Justice (PiS) party will continue its rows with Brussels over issues including judicial reforms that the EU says undermine the independence of judges and LGBT rights.
"Civic Platform is indispensable, it is needed as a force, not as a memory, to win the fight for the future against PiS," Tusk told a PO congress in Warsaw. "There is no chance of victory without Civic Platform, and our history tells us that."
The announcement of Tusk's return came after talks held behind closed doors between the new leader, his predecessor Borys Budka and Warsaw Mayor Rafal Trzaskowski, who had also been tipped for the leadership.
European Council President from 2014 to 2019, Tusk helped steer the European Union through a tumultuous period marked by Brexit and the migration crisis.
The first prime minister in Poland's post-communist history to win two terms in office, he led PO in government from 2007 to 2014.
During the global financial crisis, Poland avoided a recession under Tusk's leadership, but the government came to be viewed as increasingly out of touch with the problems of younger and less affluent Poles.
On his return to Polish politics, Tusk will still have to confront this problem, as the party, which some analysts say has struggled to define its agenda and connect with voters beyond its core middle-class, urban electorate, languishes around record lows in the polls.
"The biggest opposition party is living through the biggest crisis in its history ... Many voters who don't like PiS also don't want to vote for PO," said Rafal Chwedoruk, a political scientist at Warsaw University.
WARY VOTERS
PO, whose Civic Coalition grouping has 126 deputies in the Polish parliament against the ruling coalition's 230, has been pushed into third in opinion polls by the Poland 2050 party of Catholic journalist Szymon Holownia, whose centre-right agenda resonates with many core PO voters.
Additionally, many younger voters view the party's stance on divisive issues such as abortion and LGBT rights as too cautious.
"After six consecutive electoral losses at various levels, PO voters are losing trust in the party's ability to challenge PiS," Andrius Tursa, Central & Eastern Europe advisor at consulting firm Teneo, said in a note.
Tusk's old enemy, Jaroslaw Kaczynski, is also expected to be re-elected as leader of PiS on Saturday but faces problems of his own.
PiS has sought to maintain that its United Right coalition, of late riven with divisions, is stable and can deliver its "Polish Deal" package of economic policies, which it says will raise living standards for most Poles.
PiS swept to power in 2015 thanks to generous social spending pledges that raised living standards for many Poles, and now emphasises how changes to the tax system in the Polish Deal will leave most workers with more disposable income.
However, critics within the coalition say the changes penalise small business owners and the middle class, with three PiS members leaving the party last week amid a fresh bout of infighting.
