MOSCOW---A half-dozen Russian opposition leaders made an unusual statement Monday urging repeal of a Cold War-era trade sanction that has been defended in the United States as a means of supporting democracy and human rights here.

The Obama administration has been lobbying Congress hard to repeal the trade amendment, known as Jackson-Vanik and introduced in 1974 to pressure the Soviet Union to allow Jews to emigrate. Though its sanctions have been regularly waived for years, Russia considers it an affront. The amendment will put the United States in violation of World Trade Organization rules when Russia joins in a few months, resulting in unfavorable tariffs for American companies.

The opposition leaders said Jackson-Vanik provides modern dissidents no help, while giving Vladimir Putin an opening for anti-American propaganda.

“It helps him to depict the United States as hostile to Russia, using outdated cold-war tools to undermine Russia’s international competitiveness,” said the statement, signed by three liberal political leaders---Vladimir Milov, Vladimir Ryzhkov and Boris Nemtsov, as well as Alexei Navalny, the blogger who has helped inspire the recent anti-Putin protests.

“Those who defend [Jackson-Vanik] in order to punish Putin’s anti-democratic regime only darken Russia’s political future, hamper its economic development, and frustrate its democratic aspirations,” they said. Instead, they urge the United States to target individuals who violate human rights by denying them visas or freezing assets.

Opposition leader Alexei Navalny speaks during a rally to protest against alleged vote rigging in Russia's elections. (Misha Japaridze/AP)

Such a proposal has been introduced by Sen. Benjamin L. Cardin (D, Md.). The bill is named for Sergei Magnitsky, who accused tax authorities of using a fraudulent tax return to steal $230 million from the government. They had him arrested on theft charges instead. He died in pre-trial detention at the age of 37, his body bearing signs of beatings.

The Senate Finance Committee has scheduled a hearing Thursday on the issue of Russia and the WTO.