WARSAW (Reuters) - Poland dismissed European Commission concern on Friday that a new law on state-run media threatened media freedom, warning Brussels not to interfere in its affairs on the basis of "biased and politically-engaged" reports.

Simultaneously, the government, run by the eurosceptic Law and Justice (PiS) party, gave teeth to the new law by naming a former PiS member of parliament to head state television.

The European Union's executive has written to Poland asking how the new law tallies with EU rules on media freedoms - a sign of disquiet in Brussels that PiS policies could undermine democracy.

The PiS has long aimed to overhaul rules on public broadcasters to ensure they defend what it defines as national interests. The party has signalled earlier plans to "depoliticise" the state media.

Replying to the letter, the foreign ministry said Poland fully recognised media freedom and the Commission may have been provided with misleading information with a bias against the Polish government.

"Exposing the Polish Government to interventions inspired by unjust, biased and politically engaged enunciations might have an undesirable effect, which is to be carefully avoided," the Polish foreign ministry said.

The Commission is to discuss the issue in Brussels on Jan. 13.

NEW LAW

Under the new law, approved on Thursday by President Andrzej Duda, the treasury minister has the right to appoint heads of state-run broadcasters - a prerogative he used on Friday to name Jacek Kurski, a former PiS member of parliament, to head state television.

The heads of state media were until now appointed through public contest organised by the National Broadcasting Council, a constitutional body set up to protect the freedom of speech.

"Competences of the National Broadcasting Council, including competences the aim of which is to ensure media pluralism, stay untouched," the Polish foreign ministry said in the letter.

"There is no EU law that would require a media market regulatory body to have the power to determine the composition of management boards of public media companies," the ministry said.

The law drew criticism from within the Organization for Security and Cooperation in Europe.

In a statement, Isabel Santos, who heads the human rights committee of the OSCE parliamentary assembly, expressed alarm at "measures that undermine the independence and impartiality of media" in Poland called on its leaders to repeal it.

PiS, which ousted the governing centrist party by a wide margin in the October election, rejects such criticism. It says it has a broad mandate to redesign the country to reflect its Catholic values and independence from the EU in Brussels.

In December, the EU executive expressed concern over an overhaul of the rules governing Poland's constitutional court, demanding their introduction be postponed.

European lawmakers returned to work on Friday after the holiday break to find their mailboxes overflowing with letters from supporters of the Polish government and dismissing charges that Warsaw is eating away at democratic freedoms.

The Alliance of Liberals and Democrats for Europe (ALDE) group in the European Parliament said its lawmakers had received "hundreds of spam e-mails over the past days ... assuring us that democracy in Poland is doing fine and that now the situation is finally much better than under the previous government."

Members of the parliament's Greens group received "hundreds, probably at this point thousands of these e-mails", said a spokesman, Richard More O'Ferrall.

"PiS is using good old-fashioned propaganda that Poland remembers from the past. However, a lie told often will not become the truth," said ALDE leader Guy Verhofstadt.

(Additional reporting by Gabriela Baczynska in Brussels; Editing by Richard Balmforth)