Hungary’s beleaguered political opposition has vowed to keep up the pressure on the country’s far-right prime minister, Viktor Orbán, after a week of protests in which thousands came on to the streets of Budapest, and four MPs were roughed up by security guards after attempting to get their demands across on state television.

The protests were triggered by a so-called “slave law”, passed amid chaotic scenes in the Hungarian parliament last Wednesday, which allows employers to force employees to work overtime, and lets them delay payment for up to three years. It was passed together with legislation that provides for greater government control over the court system, the latest move by Orbán’s Fidesz party to capture independent state institutions.

A number of different opposition parties are cooperating on a joint strategy to keep pressure on the government.

“We’re closely cooperating on a daily basis, and are planning roadblocks and further demonstrations if the president signs this into law,” said Tímea Szabó, of the opposition LMP party. She also said the opposition would announce civil disobedience action, though she refused to specify what it had in mind.

Hungary: opposition MPs stage state TV sit-in – video report

On Monday evening, about 2,000 people braved subzero temperatures to protest outside the headquarters of Hungarian state television, shouting slogans about Orbán and demanding opposition MPs be let on air. About a dozen MPs spent 24 hours inside the television headquarters trying unsuccessfully to speak to viewers. After scuffles with security guards, one MP was led away in an ambulance.

The Hungarian government’s response has been to banish almost all discussion of the protest from state-controlled media. When it has referenced the protests, it has put the blame on its usual target: the Hungarian-born financier and philanthropist George Soros, favoured bogeyman of the far right across the globe.

“Brace yourselves for a new kind of democracy, one born of a carefully managed revolution by remote control,” wrote government spokesman Zoltán Kovács in a blogpost about the protests. “The revolution unfolds with protest leaders from a band of the usual suspects, many of them trained abroad and with close ties to Soros networks.”

Kovács also pointed the finger at the international media, claiming they were overselling the protests, and at the “stomach-churning opportunism” of the liberal Belgian politician Guy Verhofstadt, who tweeted his support for the protests and used the hashtag #O1G, which refers to a Hungarian meme insulting Orbán in vulgar language. Kovács described Verhofstadt as “one of Soros’s henchmen in Brussels”.

The Hungarian government has noted, with some justification, that the opposition parties enjoy marginal support, as shown by the April election, in which Orbán’s Fidesz party won two-thirds of the seats in parliament. However, the opposition say this is largely because of the almost total domination of the media by Fidesz, and add that even if they are a minority in parliament they should have access to the airwaves on publicly funded television.

“We don’t get airtime at all,” said Balázs Bárány of the socialist party, who was given a rare opportunity to air protesters’ demands on Echo TV, which is controlled by government-linked figures. “Can you imagine if Jeremy Corbyn was on air less than once a month on the BBC?”

With freezing temperatures in Budapest and only a week to go before Christmas, much smaller numbers attended Monday’s protest than on previous evenings. The prospects for any serious escalation of the protest mood seem slim.

However, the past week has galvanised the Hungarian opposition, which has previously expended as much energy on internal disputes as it has on fighting the government. There has also been cooperation with Jobbik, the extreme-right party, which has recently rebranded itself as a centrist force, as Fidesz moved to the right.