Tens of thousands of teachers, pupils and parents have rallied in Warsaw against education reforms proposed by the right-wing government. Critics say thousands of jobs could be slashed.
Rally organizers said up to 50,000 people attended the demonstration on Warsaw's central Pilsudski Square - the latest in a series of protests critical of government policies. Police put the figure closer to 30,000.
The reforms envisage changing the three-tier school system to just two levels, which means that many high schools would be closed.
Demonstrators were also concerned over proposed changes to the school curriculum, including the inclusion of "patriotic values" espoused by the ruling Law and Justice (PiS) party.
There were placards claiming Poland's education system was headed for "chaos." Slawomir Broniarz, the head of Poland's main teachers' union, was cheered as he called on Szydlo's PiS party-led government "not to destroy the assets" of Poland's current education system. Broniarz called for a "massive social front" to mobilise against the reforms.
Prime Minister Beate Szydlo told a Catholic broadcaster that schools should not only teach but also "raise" children.
Intermediate-tier schools facing closure
The PiS government wants to revert to a pre-1999 structure of eight years in primary school and then four years at high school, by closing middle schools, where pupils currently spend three years.
The middle-tier schools have been described as unsafe and ineffectual by education ministry officials.
Critics say the government proposal was drafted in haste and has many flaws that would result in a poorly devised new curriculum. Protestors on Saturday said they also feared the loss of jobs.
Protest initiator, history teacher Artur Sierawski, said the school system should not be "destroyed" but instead required "wise and well-thought-out" alterations.
Premier Szydlo told the Catholic television channel "TV Trwam": "We want that the school not only teaches but also raises [children]."
On Friday, in a rare interview with foreign media, she told Reuters that her PiS party won last year's Polish election by "reaching" voters and focusing on their needs, citing US-president elect Donald Trump as a similar practioner.
The euroskeptic, nationalist-minded PiS unseated centrists in last year's poll on promises of more economic fairness, national pride and Catholic values in public life.
Its efforts to assert control of state institutions have deeply split Polish society and raised European Union fears about an erosion of Polish democracy and media freedoms.
ipj/jm (Reuters, AFP, AP, dpa)