Lawmakers are preparing to impose harsh sanctions on Iran if the country presses forward with its nuclear program.

The U.S. and five other nations are currently negotiating with Iran in Switzerland, but members of key committee are drafting legislation to punish the Iranian regime if those diplomatic efforts fall through.

Sen. Chris Dodd (D-Conn.) chairman of the Senate Banking Committee, and Rep. Howard Berman (D-Calif.), chairman of the House Foreign Affairs Committee, are pushing new sanctions to drastically cut refine petroleum exports to Iran, the Associated Press reports.

More from the AP:

While Iran is a major oil producer, it imports gasoline and refined petroleum products. Stopping fuel shipments to Iran could have serious effects on the Iranian people.

Mideast expert Kenneth M. Pollack, director of the Saban Center at the Brookings Institution, said it was questionable whether such sanctions would work: There's bound to be leakage in the sanctions regime, Iran is quickly expanding its refinery capacity and Iran could manipulate world opinion by displaying the suffering of common Iranians, Pollack said.

The hardline positions of some in Congress, he added, could be useful to the White House as it tries to get U.S. allies on board for the administration's more targeted sanctions.