Hungarian lawmakers on Monday overwhelmingly approved a long amendment to the constitution which critics say threatens certain democratic checks and balances.
After smaller protests during the day, several thousand people gathered in the evening near the offices of President Janos Ader, asking him to veto the amendment.
The bill enshrines in the Fundamental Law, as the new constitution is called, a number of policies that were previously been struck down as unconstitutional by the country's highest court.
The amendment was passed by a vote of 265 to 11, with 33 abstentions. Prime Minister Viktor Orban's conservative Fidesz party and its small ally, the Christian Democrats, plus three independent deputies voted in favor.
The vote drew swift reaction from European institutions, which along with the United States and many Hungarian legal experts and civic groups, say it puts too much unchecked power in government hands.
"These amendments raise concerns with respect to the principle of the rule of law, EU law, and Council of Europe standards," said a statement issued by Jose Manuel Barroso, president of the EU Commission, the bloc's executive, and Thorbjorn Jagland, secretary general of the Council of Europe, a human rights watchdog.
They urged Hungary to engage with them "in order to address any concerns raised as to the compatibility of these amendments with European principles and EU law."
The evening rally was held near Sandor Palace even though President Ader was in Germany on an official visit and police closed off the area, forcing protesters to make long detours to reach their meeting point.
People in the crowd shouted, "We want democracy" and one sign held aloft read: "Should we be citizens or subjects?" Later, they marched across the Chain Bridge over the Danube River and headed toward parliament.
Among the government policies struck down by the Constitutional Court over the past months and now added to the Fundamental Law are the possibility for local authorities to fine or jail homeless people living in public areas, a ban on political campaign ads on commercial radio and TV, and a contract obliging university students who accept state scholarships to work in Hungary for years after graduation.
The amendment also prevents the president or the court from reviewing changes to the Fundamental Law other than for procedural errors and practically wipes out 20 years of jurisprudence by banning the court to refer to rulings or reasoning given while the previous constitution — originally a Stalin-era document nearly fully re-written in 1989 as communism ended in Hungary — was in force.
Speaking in the legislature ahead of Monday's vote, Prime Minister Orban did not directly address the amendment but, commenting on another matter, made it clear that the government would keep searching for ways to circumvent court decisions that go against its will.
"The court decision is scandalous," Orban said, speaking about a recent ruling in a dispute over fees which favored private utility companies over the state energy office. "The government does not accept the situation. We will fight and make new proposals ... and utility rates will be cut even further and the companies will earn even less."