WASHINGTON — A new legislative push is underway to try and shore up Congressional support for a tougher US stance on negotiations with Iran, an issue that tops the talking points for thousands of AIPAC activists hitting Capitol Hill for the organization’s legislative action day Tuesday. The push, however, is a partial retreat from an all-out offensive to approve legislation to threaten Iran with sanctions should the current nuclear talks fail.

On Monday, House Democratic Whip Steny Hoyer (D-MD) and Majority Leader Eric Cantor (R-VA) took the stage together at AIPAC to demonstrate the House’s bipartisan commitment to strong support for Israel. “For Steny and me, this issue extends beyond partisan politics,” Cantor said.

While they spoke, their staffers began to circulate a bipartisan letter to US President Barack Obama, in which they asked him to ensure that a final deal with Iran includes Israel’s demand for a dismantlement of Iran’s uranium enrichment program.

The letter, Hoyer said, “underscores our common commitment to ensure that Iran does not build, acquire or develop a nuclear weapon.

The House letter, like a letter that AIPAC activists plan to push senators to sign Tuesday, does not explicitly call for a new sanctions bill, like the Nuclear Weapons Free Iran Act, to be passed. Instead, the Cantor-Hoyer letter – similar to a letter co-sponsored by Senators Robert Menendez (D-NJ) and Lindsay Graham (R-SC) – takes a tough stance on conditions for a final agreement.

The Obama administration has pressured congressional Democrats against passing legislation that would threaten Iran with additional sanctions while talks are underway toward a comprehensive nuclear deal with Tehran.

Unlike the Nuclear Weapons Free Iran Act, which AIPAC has struggled to sell to Congress, the letter circulated in the House does not force House Democrats to chose between support for contingent sanctions legislation and their loyalty to the Democrat-controlled administration.

Instead, the Cantor-Hoyer letter expresses their hopes that any comprehensive agreement “will require dismantlement of Iran’s nuclear weapons-related infrastructure, including facilities for enrichment-, heavy water- and reprocessing-related facilities, such that Iran will not be able to develop, build, or acquire a nuclear weapon.”

The letter also calls for an agreement that will “include stringent transparency measures to guarantee that Iran cannot develop an undetectable nuclear weapons breakout capability,” and require Iran to fully and verifiably implement its Safeguards Agreement with the International Atomic Energy Agency, ratify and implement the Additional Protocol, answer pending IAEA questions, and comply with the transparency measures requested by the Director General of the IAEA, as well as with any additional verification and monitoring measures necessary to ensure Iran is abiding by the terms of any agreement.”

Stopping far short of the preemptive sanctions approval that would be part of the Nuclear Weapons Free Iran Act, which details penury sanctions in advance if talks fail with Iran, the House letter merely states that it hopes that Congress will be enabled to “act swiftly to consider additional sanctions” in the event that “no agreement is reached or Iran violates the interim agreement.”

AIPAC activists are expected to push their assigned representatives to sign on to both this letter and the letter forwarded by Menendez and Graham, which is being circulated in the Senate.

According to the lobbying training sheets distributed by the organization, AIPAC activists will push Senators to commit to supporting the Nuclear Weapon Free Iran Act, which has so far fallen short of the number of Democratic co-sponsors that the bill’s proponents had hoped for.

Menendez fired up conference attendees hours before they took to the Hill, talking up the importance of the Nuclear Weapons Free Iran Act, which he co-sponsored with Sen. Mark Kirk (R-IL).

“To those who believe that — if negotiations do not result in a deal or if Iran breaks the deal — we can always impose new sanctions — let me be very clear: If negotiations fail, or if Iran breaks the deal, we won’t have time to pass new sanctions,” Menendez explained. “Even if Congress were to take-up and pass new sanctions at the moment of Iran’s first breach of the Joint Plan of Action — or if they do not reach an agreement that is acceptable — there will be a lag time of at least 6 months to bring those sanctions on line, and at least a year for the real impact to be felt.”

Speaking on Monday evening, Secretary of State John Kerry offered a different spin on the situation, saying that Menendez’s bill was unnecessary because Congress could approve new sanctions in a matter of hours if it was necessary.