Private media groups in Poland suspended their news coverage on Wednesday in a 24-hour protest at a proposed tax on advertising they fear would undermine independent journalism.

Channels run by the two biggest independent broadcasters, TVN and Polsat aired black screens with the message “This is where your favourite programme was supposed to be”.

Meanwhile, several private radio stations, including TOK FM and Radio Zet, replaced normal programmes with a message on a loop, accusing the government of wanting to “destroy independent media”.

“We are protesting so that we can convince you what Poland will look like without independent media,” ran the message to listeners. “We apologise to you, our listeners and business partners, for the change to today’s schedule, but we have no choice.”

Poland’s conservative-nationalist government says the proposed levy on advertising revenues — which is under consultation and would vary from 2 to 15 per cent depending on the size of the advertising revenues, the type of media and the product advertised — would help support the health system, which has been hit by the coronavirus pandemic.

The government expects the plan to raise 800m zlotys ($217m) a year. Draft legislation envisages that 50 per cent would go to the public health fund, 35 per cent to a new government-controlled fund to support “culture and national heritage in the media sphere”, and 15 per cent to a fund for protecting monuments.

“This is a solidarity payment, which applies in many EU countries,” Piotr Muller, a government spokesman, told the state broadcaster TVP, which continued to broadcast as normal. Asked about the protest, he said it was not surprising that “everyone wants to avoid taxes”.However, private media groups see the proposals — which come two months after state-controlled oil refiner Orlen bought 20 of Poland’s 24 regional newspapers in a deal that sparked concerns over journalistic freedoms — as part of a broader deterioration of the media environment.

Since the ruling Law and Justice party came to power in 2015, Poland has tumbled from 18th to 62nd place in the World Press Freedom Index, leaving it below Niger and Armenia.

In an open letter to the government, 45 media organisations branded the proposals “extortion”, and warned that the tax could lead to the “weakening, or even liquidation” of some Polish media companies.

They added that the plans would limit their ability to produce quality and local content, and “deepen the unequal treatment of groups active in the Polish media market”, describing the “asymmetric” impact of the proposals on different media groups as “scandalous”.

In a blistering op-ed, Boguslaw Chrabota, editor of Rzeczpospolita, a centrist daily, said that the proposed tax had left media groups “rubbing our eyes in amazement”.

“Is this really a good time for additionally taxing the media? Is this frightening short-sightedness? Or maybe something else? Systemic revenge for the fact that we are fulfilling our constitutionally guaranteed role of keeping an eye on the public authorities? Is this why there is a desire to destroy us?” he wrote.

The Polish proposals also drew attention from the EU and the US.

Christian Wigand, a spokesman for the European Commission, told a press conference that the commission was aware of the proposals and expected EU states to ensure that “fiscal or other policies will not affect their duty to ensure a free, independent and diverse media ecosystem”.

Meanwhile, Bix Aliu, chargé d’affaires at the US embassy in Warsaw, said on Twitter that “free media are a cornerstone of democracy”. “The US will always defend media independence,” he wrote.