BUDAPEST, Hungary — Opponents of the Hungarian government’s efforts to oust the country’s president gathered for a protest in the capital Budapest on Thursday after being called to action by the former autocratic prime minister, Viktor Orbán.

The protest drew several thousand people to the presidential offices at the opulent Sándor Palace in Budapest’s Castle District, where demonstrators spoke out in defense of President Tamás Sulyok, whom the new center-right government has vowed to remove from office with a constitutional amendment.

After defeating Orbán in a blowout election in April, bringing an end to his 16 years in power, Hungary’s new pro-European prime minister, Péter Magyar, has taken action to dismantle what he calls Orbán’s “mafia” by removing numerous political appointees and heads of institutions viewed as having facilitated Orbán’s autocratic regime.

The constitutional amendment, set to go to a vote next week, would end Sulyok’s term, as well as set term limits for members of parliament, implement reforms to the judiciary and create a new authority tasked with uncovering alleged financial abuses by Orbán’s government.

But Orbán and his far-right Fidesz party, long accused of dismantling Hungary’s democratic institutions while in power, have declared that the move to remove Sulyok is an assault on the rule of law and democratic norms, and the first steps toward a dictatorship.

One protester, Krisztina Nemerkényi, said Thursday that the demonstration was not about the person of Sulyok, “but about the office.”

“The point is not whether Tamás Sulyok is popular or not, but that this is simply unacceptable in a democracy,” she said.

Magyar has argued Sulyok failed to live up to his role as president by neglecting to stand in the way of antidemocratic steps by Orbán’s government. He promised repeatedly to remove Sulyok during the election campaign, and points to his party’s two-thirds majority in parliament as a clear mandate from voters to fulfill that promise.

While mostly a ceremonial role, Hungary’s president is responsible for signing legislation into law and has the power to send bills passed by parliament to the constitutional court for review. That’s raised concerns among supporters of the new government that Sulyok, an Orbán-era appointee, could use that power to obstruct its plans.

Ahead of Thursday’s protest — titled “Stop Tyranny” — Orbán vigorously promoted the event on social media, but did not attend. Since April, his Fidesz party, which organized the demonstration, has struggled to recover from its major election defeat.

János Pócs, a Fidesz lawmaker, told The Associated Press at the protest that while Fidesz had passed many constitutional amendments — making 15 changes to the document that it unilaterally authored in 2011 — it had done so “always in the interest of the country, in order to protect the country, but not for the sake of dictatorship.”

After taking office in May, Magyar’s government went quickly to work fulfilling other campaign promises, such as suspending the news service of Hungary’s public television and radio, which Magyar has argued served as a “propaganda factory” for Orbán’s party.

It has also implemented an 8-year term limit for prime ministers and ousted the heads of the national security and intelligence agencies that served under Orbán’s tenure. It also succeeded in unlocking 16.4 billion euros (around $19 billion) in European Union funds for Hungary by enacting rapid reforms to roll back the democratic backsliding that occurred under Orbán.