The scathing report on Ankara's EU candidacy, originally due for release before the vote that returned President Recep Tayyip Erdogan's party to power, praised Turkey for housing Syrian refugees and for cooperating on the migration crisis.
But it was severely critical of the domestic situation in Muslim majority Turkey, saying that under Erdogan there had been "serious backsliding" on freedom of expression and that the judiciary had been undermined.
Turkey's commitment to joining the 28-nation bloc was "offset" by domestic actions that "ran against European standards", it added.
"The new government formed after the repeat election on 1 November will need to address these urgent priorities," the summary said.
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The report highlighted criminal cases against journalists and writers, intimidation of media outlets and changes to Internet law.
"After several years of progress on freedom of expression, serious backsliding was seen over the past two years," it said.
Turkey had meanwhile seen a "severe deterioration of its security situation" including a huge suicide bombing on a peace rally just before the election, and the collapse of a ceasefire with Kurdish militants.
The harsh report had been expected to be released in October but was held back until after the elections, in which Erdogan's AKP party stormed back to a majority.
Its release comes just over a month after the EU announced a a refugee cooperation deal with Turkey, the main launching point for migrants coming to Europe, including a possible three billion euros (USD 3.3 billion) in aid.