Legislation in the U.S. House of Representatives aimed at beefing up economic sanctions against Iran could prohibit the United States from negotiating with the country, Reps. Dennis Kucinich (D-OH) and Fortney Pete Stark (D-CA) warned in a letter to their colleagues.

The Iran Threat Reduction Act, H.R. 1905, is expected to pass this week under a suspension of House rules. The bill has a whopping 368 co-sponsors.

Section 601 of the bill would make it illegal to contact any Iranian official who “presents a threat to the United States" unless the President certifies to Congress that not talking to the Iranian official “would pose an unusual and extraordinary threat to the vital national security interests of the United States” 15 days prior to that contact.

"This language effectively ties the hands of the U.S. government by posing unnecessary restrictions on already difficult diplomatic engagement with Iran," Kucinich and Frotney wrote in their letter. "It would pose obstacles for the President to press Iran on its nuclear program in negotiations and would prevent Members of Congress from potential dialogues with Iranian parliamentarian."

Rep. Ron Paul (R-TX) said in early November that the legislation was a precursor to war with Iran.

Kucinich and Frotney continued: "As we only now extricate ourselves from devastating military confrontations in Iraq and Afghanistan, we must not allow the United States to be plunged into yet another disastrous war. Tensions with Iran are escalating rapidly and it is crucial we do everything necessary to prevent war, not take diplomatic options off the table."

"U.S. policy toward Iran for the last three decades has primarily taken the form of economic sanctions, threats and isolationism. None of these things has created meaningful change in the behavior of the Iranian government or achieved the transparency we seek. Please join us in opposing this bill," they concluded.