Turkey's Islamic-rooted ruling party will press ahead with its plan to criminalize adultery, despite earlier statements that the controversial measure had been shelved, a party member said Thursday.

The decision came two days after the party said it was abandoning the plan after protests from women's groups and warnings from the European Union (search) that it could jeopardize Turkey's chances of joining.

In retooling its proposal, the party has replaced the word "adultery" with "sexual infidelity," a senior member of the ruling party told The Associated Press, speaking on condition of anonymity.

Senior opposition figure Ali Topuz — whose party rejects the adultery proposal — said he and other opposition lawmakers are preparing to walk out of parliament if the measure is resubmitted.

"There is pressure on us, we can never accept this," Topuz told CNN-Turk television. "If the adultery proposal comes to the parliament ... then they bear the responsibility."

"We would do anything we can at the highest level to paralyze the parliament."

The push to outlaw adultery comes as Turkey revises its 78-year-old penal code in preparation for hoped-for EU membership. Though the proposed adultery ban has alarmed EU officials, Ankara has been trying to tack it onto the penal code revisions — apparently to appease Prime Minister Recep Tayyip Erdogan's (search) conservative and devoutly Islamic base.

Some Europeans and Turkish secularists fear Erdogan may be trying to steer the country away from its more than eight decades of strict secularism, instituted by Kemal Ataturk (search), who founded modern Turkey out of the ruins of the Ottoman Empire after World War I. Turkey's 70 million people are predominantly Muslim.

During a parliament session Thursday, hard-line lawmakers of Erodogan's Justice Development Party (search) forced a two-hour suspension of voting on penal code reforms, objecting to several amendments apparently aimed at strengthening secularism.

The contested amendments would ban Islamic clerics from criticizing the government, imprison non-clerics for wearing Islamic attire without official permission, and close down unauthorized Quran courses.

On the revised adultery ban, CNN-Turk reported that Erdogan told his lawmakers to prepare a proposal in line with the demands of the public — which he insists wants adultery outlawed.

Amid the tensions, hard-liners met with Erdogan and Justice Minister Cemil Cicek to discuss the proposals.

"We will discuss all controversial articles including adultery," the semiofficial Anatolia news agency quoted senior lawmaker Haluk Ipek as saying before the meeting.

Ipek insisted the proposal to outlaw adultery was never dropped from the agenda, disputing statements from other senior party officials.

"No doubt, we attach importance to the protection of the family," Foreign Minister Abdullah Gul said Thursday, reflecting deep uneasiness within his party. "No doubt, this is also important for Europe."

The dispute immediately sent Turkey's jittery stock market down.