The delay is the latest chapter in a saga in which certain Turkish political circles tried to insert a law into the code that would have outlawed adultery. The law, initially backed by the ruling AKP party, was scrapped on Tuesday after sharp criticism from the EU.
It now appears to be back on the agenda and threatens to derail a process that a week ago seemed to be leading toward accession talks between the EU and Turkey.
Jean-Christophe Filori, a spokesman for the European Commission, told reporters in Brussels today that the commission views the delay in instituting the new penal code "with concern."
"We understand also that a number of provisions in this draft penal code have been subject to -- let's say -- political approval in Turkey," Filori said. "But once again, I'm just saying that this penal code is important and we need it."
Filori said the delay appears to be due to attempts to reintroduce adultery as a criminal offence.
He reiterated the EU's opposition to any such law. He said it would send "the wrong signal" and cast doubt on the direction of Turkey's reform efforts and thereby jeopardize Turkey's accession chances.
"The new penal code in Turkey is of the utmost importance in Turkey's political reform process," Filori said. "It addresses several issues directly linked to the political [entry] criteria of Copenhagen and therefore it plays an important role in our assessment on 6 October."
Some officials predicted the commission report may be delayed by a week, but for reasons unrelated to Turkey. If the report is positive, officials said, EU member states are almost guaranteed to act on it in December, and agree to launch accession talks the following spring.
The new penal code is especially prized in Brussels for addressing a number of fundamental concerns relating to women's rights.
Another important facet of the code is action against torture, a key EU concern. Filori said an EU "fact-finding mission" on torture will return from Turkey tonight. Acknowledging the immense political sensitivity of Turkey's membership prospects, the commission is keeping its cards close to its chest.
Filori said today that "no clarity" exists even on the issue of whether the commission, when assessing Turkey's preparations, would be obliged to choose between a simple "yes" or a "no."
Other officials said it is virtually certain some restricting conditions would accompany any positive decision. For example, even if they become full members of the EU, Turkish citizens are unlikely to be granted full access to the labor markets of other member states.