WASHINGTON (CNN) -- They are vying for the presidency from opposite sides of the political spectrum, but Sens. Barack Obama, D-Illinois, and Sen. Sam Brownback, R-Kansas, are teaming up to sponsor legislation that seeks to encourage divestment from companies that support Iran.

"The time has come for the federal government to assist citizens, institutional investors, and state and local governments in divesting from companies that support the Iranian regime," Brownback said in a statement.  "The Iranian regime is the world's biggest state sponsor of terror, proudly flaunts an illegal nuclear program, and continues to violate the basic human rights of the Iranian people."

Under the bill, the federal government will publish twice a year a list of companies that invest $20 million or more in Iran's oil and gas industries, and authorize state and local governments to divest from the companies.