(HELSINKI) - Finland's Foreign Minister Timo Soini has lashed out at the European Union for its unprecedented probe into controversial legal changes in Poland, saying the bloc is trying to 'dictate' the country's internal affairs.

"The un-elected EU bureaucrat cannot walk over an independent, elected decision-maker," the minister, who heads the populist and anti-immigration Finns Party, wrote in a blog post published Wednesday evening.

"Free and honest elections were held in Poland. (But) the EU wants to dictate Poland's affairs. History hasn't taught anything at all to the EU faithful, it seems," wrote Soini, who has long been an outspoken critic of the EU.

The EU on Wednesday launched an investigation into controversial reforms introduced by Poland's new right-wing government to see if they violate the bloc's democracy rules and merit punitive measures.

The move comes amid growing concern over reforms to Poland's constitutional court and increased control over state media adopted by the conservative, eurosceptic Law and Justice party (PiS), which swept to power in October.

European Commission vice-president Frans Timmermans said Wednesday that rulings by Poland's constitutional court were not being respected by the new government, and that he is worried that the country's new media laws could curb freedom of expression.

The EU will review Poland's answers by March.

Brussels introduced the "rule of law" mechanism in 2014, giving the 28-nation bloc the right to investigate and if necessary punish any member state which violates key EU democratic and rights norms.