Warsaw heads to the polls on Sunday in a referendum on whether to dismiss the mayor of the Polish capital in a key test for Prime Minister Donald Tusk's increasingly unpopular government.
Hanna Gronkiewicz-Waltz, who has been mayor of Warsaw since 2006, is the vice-president of Tusk's Civic Platform (PO), which has suffered a series of defections and anti-government protests in recent months.
Recent opinion polls also show the PO lagging behind former prime minister Jaroslaw Kaczynski -- the twin of late president Lech -- and his populist right-wing opposition.
The referendum, requested by the opposition about a year before municipal elections, will require at least a 29 percent voter turnout to be valid.
Kaczynski's Law and Justice (PiS) party called on voters to "fulfill their civic duty".
A poll published Thursday showed 32 percent of voters planned to participate in the referendum and 74 percent wanted the mayor's departure.
Gronkiewicz-Waltz, 60, former governor of the Polish central bank, has been criticised for her management of infrastructure in the capital and the "arrogance" of the municipal administration.
"In fact, it is not about Warsaw, or its mayor. A large part have simply found an excellent occasion to make this referendum a training ground before the electoral battle in 2015," when the next legislative elections will be held, sociologist Jansuz Czapinski said in a debate earlier this week.