RIO DE JANEIRO — Tens of thousands joined in demonstrations across Brazil on Wednesday to protest big cuts in federal funding for public education, the first nationwide rallies organized against far-right President Jair Bolsonaro since he took office Jan. 1.

Avenues and public squares in Sao Paulo, Brasilia, Rio de Janeiro, Salvador and Recife were jammed as students and teachers marched against the decision to pare $1.85 billion from funds for the public education network, from elementary schools to universities.

Speaking during a visit to Dallas, Texas, Bolsonaro dismissed the protests, calling student demonstrators “useful idiots” who have “nothing in their heads” and are being manipulated by “a sly minority” in federal universities.

Education experts, professors and students say they are particularly worried about the government freezing 30% of the discretionary budgets at all federal universities, money that goes to pay such things as utility bills, security, cleaning and maintenance work.

Nilton Brandao, president of one of Brazil’s largest teacher unions in higher education, said the second semester at universities, which in Brazil run August-September, will be compromised due to the lack of financing. Brandao said that if the decision is not reversed, universities may not be able to open.

Brandao said the new government should be following the previous administration’s 10-year education roadmap that was implemented in 2014.

“We (in Brazil) approved a national education plan, with clear objectives to meet. It’s a project that has been approved and that is still in vigor,” he told The Associated Press. “The government is ignoring this plan. They don’t want to discuss education.”

Since the early stages of his presidential campaign, Bolsonaro has repeatedly vowed to improve Brazil’s underperforming education system, mostly by ousting what he considers a deeply engrained “Marxist ideology” and by increasing security in violent schools. After assuming the presidency, Once in the presidential office, Bolsonaro spoke of plans to revise school textbooks to excise references to feminism, homosexuality and violence against women.

On Wednesday, Bolsonaro said he wished he didn’t have to implement the cuts but that he was legally obligated to do so as they are part of a wider effort to slash all government spending .

“There is no way around it, we need the (cuts),” he said.

In Brasilia, thousands of protesters carried banners down the Esplanade of Ministers past the lower house of congress, where the education minister Abraham Weintraub had been summoned to testify about the budget cuts.

Weintraub told lawmakers during a heated debate that the current government was not responsible for the current “disaster” in education, which it inherited from previous administrations.