The House of Representatives is poised to vote on greatly increasing the economic pressure on Iran over its nuclear program through sanctions that could cripple that country's energy sector.
HR-850, the Nuclear Iran Prevention Act of 2013, would seek to slash Iran's oil sales to 250,000 barrels a day by the end of 2014, from the current 1.25 million barrels. Iran's oil production has already been halved over the last two years, according to the International Energy Agency.
A vote is expected on Wednesday or Thursday of this week.
The bill calls for tightening the exemptions now granted by the United States to several countries that still buy Iranian oil. It also calls for further sanctions against Iran's auto sector and its mining industry, and it seeks to punish companies that work with Iran's financial system, including its central bank.
"The oil provisions in the bill will be seriously injurious to Iran if countries continue to cut back on deliveries from Iran," said Kenneth Katzman, who analyzes sanctions on Iran for the Congressional Research Service.
The bill would also designate Iran's powerful Revolutionary Guard a "Foreign Terrorist Organization."
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Currently, 374 of the 435 members of Congress have signed on as co-sponsors of the bill, making passage almost certain. However, Congressional insiders told CNBC that the bill will likely face changes in the Senate, and that senators will likely face White House pressure to delay a vote.