The announcement came on Tuesday by surprise and from an unexpected source.
After a 20-minute meeting, opposition leader Deniz Baykal, flanked by two top government ministers, told reporters: "No motion that does not bear the signatures of both parties will be submitted to the assembly."
Although none of the men mentioned adultery, it meant the plan by Prime Minister Recep Tayyip Erdogan's Justice and Development Party (AKP) had died a quiet death.
"I am very pleased with this turn of events," Baykal said, stressing that the bill to do away with Turkey's 78-year-old criminal code, adapted in 1926 from that of Italy, was the result of more than a year's work, often at bipartisan level.
Flanking Baykal along with the AKP Justice Minister Cemil Cicek, Foreign Minister and Deputy Prime Minister Abdullah Gul told insistent journalists: "Do not reduce the whole reform bill to just adultery."
Gul is acting for Erdogan, who is on an official visit to Tajikistan.
As the furore mounted over the adultery clause, it tended to push into the background the many aspects of the bill viewed as positive.
The bill, among other things, brings heavier penalties to the crimes of torture and child molestation; unless explicitly ordered by a judge or a prosecutor, it forbids downgrading virginity tests, it bans child pornography, child abuse, the trade in human organs, environmental pollution and computer piracy.
Erdogan had defended the adultery clause as part of efforts to "protect the unity of the family."
EU bid damaged
But leaders of the European Union, of which Turkey hopes to become a part of, had joined a growingly vocal Turkish opposition to denounce the plan, with Britain, Spain, Germany and the EU Commission openly warning that it would damage Turkey's EU bid.
Some European countries have said
the bill would endanger Turkey's bid
The minister of culture and tourism, Erkan Mumcu, 41, was the first cabinet member to openly oppose the measure, saying on Monday that criminalising adultery has "no social value."
Ruling party deputies interviewed on the parliamentary television channel before an AKP caucus on Tuesday morning were unanimous that the single issue had overshadowed all the other work done on the bill.
Many said the clause had not yet been submitted, and some said they hoped it never would.
Gul said before his party caucus that "a clause that does not even exist" is casting a pall over "an important and radical reform."
"Turkey does not deserve this," Gul said. "Everything is openly discussed in this country. ... The Assembly will meet and the deputies, who represent the people, will act according to what they believe and what they deem to be right."
Debate on the bill is expected to last at least a week, "perhaps even two," Gul told the caucus.
As he spoke, about 500 demonstrators - mostly women, but also members of human and gay rights groups - marched on parliament, waving banners and chanting slogans against the plan to make adultery a jailable offence.
Demonstrators marched against
adultery being criminalised
The march was peaceful apart from some minor scuffles, and CHP deputies emerged from the sprawling parliamentary complex to greet the demonstrators and usher them into the House to listen to the debate.
The controversy came as Ankara, an EU candidate since 1999, awaits a crucial 6 October report by the EU Commission that will recommend whether to launch membership talks.
The report will serve as a basis for a final decision on 17 December by European leaders on whether and when to set a date for the start of negotiations.