Serbian opposition parties said on Monday they had started to boycott parliamentary sessions in protest against what they see as the increasingly authoritarian rule of President Aleksandar Vucic and his ruling Serbian Progressive Party (SNS).

Opposition parties and their backers accuse Vucic and the SNS of stifling media freedoms and carrying out attacks on political opponents and journalists in Serbia, a country seeking to join the European Union. They deny the accusations.

The boycott move comes amid weekly protests by thousands of people that began in December and have spread from the capital Belgrade to a dozen other towns and cities. The protesters and opposition are also demanding Vucic’s resignation and snap elections.

In a statement, the opposition parties said their lawmakers would boycott plenary sessions, but would remain inside the parliament building, where they would continue to hold news conferences and briefings until their demands are met.

“We are boycotting the parliament not because… they [the ruling coalition] disrespect us but because we have an obligation to the thousands who are protesting … to demand a normal system and a normal Serbia,” Sanda Raskovic Ivic, head of the centre-right Democratic Party of Serbia, told reporters.

Ivic’s party belongs to the Alliance for Serbia, a heterogeneous grouping of political parties, trade unions and civic groups.

Vucic, a nationalist firebrand during the Balkan wars of the 1990s who has become an advocate of closer ties with the West, has said he will not bow to the protesters’ demands.

Last week he began touring the country to rally his own supporters. He has not indicated whether he will call snap elections for the spring.

The opposition’s boycott decision will not halt the work of parliament, where the SNS and its Socialist Party ally hold 160 of the 250 seats, a comfortable majority, but it could undermine the ruling coalition’s credibility.

According to opinion polls, Vucic and the SNS enjoy the backing of around 50 percent of voters, while the opposition parties could jointly garner around 15 percent.