The Polish President, Andrzej Duda, has signed controversial laws enabling the new conservative government to appoint the heads of public TV and radio, as well as civil service directors.
The treasury minister will have the right to hire and fire the broadcasting chiefs - a role currently in the hands of a media supervisory committee.
European media watchdogs have protested at the move. The EU Commission suspects Poland may be jeopardising EU values.
Poles are hotly debating media freedom.
A Polish presidential spokeswoman, Malgorzata Sadurska, said Mr Duda had signed the laws because he wanted the state media to be "impartial, objective and reliable".
The Law and Justice Party (PiS), which won a clear majority in October elections, argues that journalists on public service channels are biased against it in their coverage.
Most Poles tune in to the public TVP channels, as well as public radio - which includes many regional stations.
The BBC's Adam Easton in Warsaw says incoming governments in Poland tend to put their own people in to run large state companies, institutions, and the public media - but the PiS is going faster and further this time.
The PiS is Eurosceptic, committed to social welfare and keen to promote traditional Catholic values.
The European Commission - the EU's top regulator, enforcing EU treaties and standards - will debate the rule of law in Poland on 13 January.
Under the EU's new rule of law mechanism, the Commission can put pressure on a member state and, in the last resort, remove its voting rights in the European Council, where ministers decide EU policy.
The mechanism, in Article Seven of the Lisbon Treaty, has not been invoked before.
But Commission President Jean-Claude Juncker stressed that such a step was not yet being considered.
"We are not there, I don't think we will get to that point," he said. "Let's not overdramatise... We have to have friendly and good relations with Poland so our approach is very constructive. We are not bashing Poland."
The PiS has also controversially changed the rules for Poland's constitutional court. Critics say the changes undermine the court's responsibility for holding the government to account.