The turbulence erupted after Mr. Samaras unilaterally shut down the Hellenic Broadcasting Corporation, known as ERT, on June 11 in an attempt to meet the demands of Greece’s foreign lenders that it fire 2,000 public sector workers by the end of June. Democratic Left opposed the move, as did the Socialist party, Pasok.

On Thursday, Mr. Kouvelis criticized Mr. Samaras for keeping the broadcaster dark even after one of Greece’s highest courts ordered it put back on the air. “For us it is an issue of democratic legitimacy,” he said. Showing deft political acrobatics, he said Friday that his party would support the government in economic reform bills to be put before Parliament in the coming weeks.

Together, New Democracy and the Socialists have 153 and possibly up to 157 seats in the 300-seat Parliament with the rumored return of defectors from their ranks. It was not immediately clear on Friday whether the government would have to call a confidence vote in addition to reshuffling the cabinet.

The Socialist leader, Evangelos Venizelos, said Thursday that the closing of the broadcaster “offended citizens’ democratic sensibilities,” but explained why his party would stay in the government. “The question is that of early elections or not,” he said. “People don’t want elections, they want a government that can operate quickly, properly, efficiently.”

Experts said the Socialists did not want to bring down the government, and Mr. Samaras did not want to call new elections to consolidate his mandate, because New Democracy has only a narrow lead in opinion polls over the leftist opposition party, Syriza, and the government is also wary of the surge in popularity of the neo-Nazi Golden Dawn party.

But in a volatile climate, the shutdown of the state broadcaster could devolve into something more unpredictable. Since June 11, the 2,600 employees of ERT have been illegally occupying the building’s headquarters in northern Athens and broadcasting online after the government cut the electricity to its satellites. It remained to be seen how Mr. Samaras intended to remove the workers from the premises.

The Finance Ministry issued a statement on Friday, calling on employees “to evacuate the premises of the former ERT to allow for the unhindered and immediate implementation of the Council of State’s decision,” referring to a ruling by a top Greek court that upheld the closing but called for the broadcaster’s signal to be restored immediately.

The statement added that the government was drawing up a plan for the 2,000 positions deemed necessary to run an interim network, an apparent reference to the three-month contracts Mr. Samaras referred to in a televised address on Thursday. Calling ERT a bastion of political patronage, fed for decades by his own party and the Socialists, Mr. Samaras has pledged to reopen the broadcaster in three months with fewer employees.