Riot police stormed the former Greek state television headquarters in Athens and evicted dozens of journalists who were fired five months ago.
The move ended a protracted sit-in against the broadcaster's closure.
The government took ERT off the air in June to meet a target for public sector job cuts set by foreign lenders.
Police carried out the pre-dawn eviction as inspectors from European Union and International Monetary Fund lenders were in Athens reviewing Greece’s progress.
"I was on air when riot police stormed into the studio and ordered me to shut the microphones and leave," said Nikos Tsibidas, spokesman for ERT's radio workers union.
"I've never seen anything like this before; it's barbaric and indicative of the kind of democracy we have in this country."
Greece's anti-bailout opposition denounced the police raid and forced a vote of confidence against the government.
Prime Minister Antonis Samaras's government is expected to win the vote, which will be held late on Sunday, without much trouble.
Minor scuffles broke out between some protesters and riot police, who had cordoned off the area and blocked the entrance to the building that has been draped for months with banners reading "ERT Open" and "No to layoffs".
Police fired a few rounds of tear gas to disperse small groups of protesters and briefly detained four people for resisting authorities during the raid, officials said.
Some of the journalists, who have kept ERT running with an illegal news feed over the Internet for five months, refused to leave the yard of the building, where hundreds of chanting ERT supporters rallied.
"This is how fascism works, slyly and in darkness," said Adrianna Bili, a former ERT employee, after she and other protesters were evicted from the building.
The channel showed footage of an empty newsroom and images of the headquarters with the text "ERT belongs to all Greeks" running across it.
The government said the police operation was carried out to "apply the law and restore legality."
Government spokesman Simos Kedikoglou, a former ERT journalist himself, said ERT was "under illegal occupation".
Inside the building, police checked in the presence of a prosecutor whether facilities and equipment had been damaged since the broadcaster's closure.
Under lender pressure, the government singled out ERT as a paragon of public waste and mismanagement in Greece.
Still, the decision to silence ERT and fire its 2,600 employees to please EU/IMF lenders shocked many in Greece and reduced Mr Samaras's majority in the 300-seat parliament to five.
The government has since launched a new television channel called Public TV, or DT, in which about 600 people have been hired, many of them from the defunct ERT.
The main opposition Syriza party denounced the police raid as authoritarian and said it was just a precursor for the tough, new austerity measures the government was preparing.
