Several leaders of Russia's fragmented opposition urged the United States on Monday to remove a largely symbolic Cold War trade provision, in a rare display of unity.

They included anti-corruption blogger Alexei Navalny and other organisers of demonstrations against Vladimir Putin who recognise the need to refocus their protest movement away from the street after his election as president but have found a common policy agenda elusive.

In an open letter they criticised U.S. politicians who say the repeal of the Jackson-Vanik amendment, a 1974 legal provision that still affects trade with Moscow, would benefit only Putin and his cronies and that its removal should be tied to an improvement in Russia's human rights record.

We, leading figures of the Russian political opposition, strongly stand behind efforts to remove Russia from the provisions of the Jackson-Vanik Amendment, the letter said.

Although there are obvious problems with democracy and human rights in modern Russia, the persistence on the books of the Jackson-Vanik Amendment does not help to solve them at all.

The group said that the trade restrictions imposed under the amendment limited Russia's competitiveness in international markets and trapped it in its petro-state model of development.

Jackson-Vanik is not helpful in any way - neither for promotion of human rights and democracy in Russia, nor for the economic interests of its people, the group said.

The 1974 Jackson-Vanik amendment tied trade relations with the former Soviet Union to the rights of Jews and other religious minorities to emigrate freely.

The Soviet Union collapsed in 1991 and Russia has been in compliance since at least the 1990s.

The provision contradicts the global trade rules defined by the World Trade Organization (WTO), which Russia is set to join. The Obama administration is pushing the U.S. Congress to strengthen trade ties with Russia by repealing Jackson-Vanik, and an intense debate on the matter is expected in Congress later this year.

The U.S. envoy to Russia said on Monday that he had been telling U.S. lawmakers they could not make Russia more democratic by refusing to lift Jackson-Vanik.

If you don't believe me, ask Navalny, Ambassador Michael McFaul said in Washington, referring to the open letter Navalny and others signed in Moscow.

Instead of clinging to a Cold War amendment, U.S. lawmakers who want to advance the cause of democracy in Russia should authorize $50 million proposed by the Obama administration to help fund human rights organizations in Russia, McFaul told an audience at the Peterson Institute.

McFaul said he was somewhat shocked by what he described as the anti-Americanism of the recent Russian presidential campaign, but added that he was waiting to see whether it would subside.

The six signatories to the open letter in Moscow included liberal politician Vladimir Ryzhkov and former Deputy Prime Minister Boris Nemtsov as well as others who organised a wave of protests in Moscow following a disputed parliamentary election on December 4.

Putin, who won a six-year term as Russia's president in an election on March 4 which international observers say was skewed in his favour, has accused the opposition of serving the interests of Western governments.

The opposition, which includes liberals, nationalists and leftists, has struggled to united around a common agenda beyond their main demands for fair elections, general political reforms and calls for Putin to leave office.

(Additional reporting by Susan Cornwell in Washington; Reporting by Gleb Bryanski, Editing by Timothy Heritage and Paul Simao)