The European Commission said on Saturday it wanted to know from Ankara if its penal code reforms, including a controversial ban on adultery, will be in place or changed before a key EU decision on talks next month.
The Turkish government put its penal code reform on hold on Thursday after the centre-left opposition blocked its efforts to include the clause criminalising adultery.
Penal code reforms are a step the EU sees as crucial if it is to open talks on Turkish EU membership.
"We have a problem of timing," Enlargement Commissioner Guenter Verheugen told reporters after talks with Turkey's ambassador to the EU, Oguz Demiralp.
"So far our assessment was based on the assumption that the penal code would be adopted before the Commission must make its decision."
He said he understood the adoption of the code had been postponed by Ankara and no new date had been set.
"I have asked the ambassador to get clarification from his government whether and when the penal code will be adopted, and whether it will be substantially changed," Verheugen added.
The Commission is due to give its assessment on October 6 on whether Turkey is ready to start accession talks with the bloc, and this has been thrown into question by Ankara's delays to adopting the code.
"The Commission is working night and day to prepare the package for adoption ... on October 6," Verheugen said but he made clear the report would still come out on October 6. Asked if there could be a delay, he replied: "Absolutely not ... I do not see a reason why we should delay."