Russian Lawmaker: Nuclear Pact with US at Risk

MARRAKESH, Morocco (Reuters) - A nuclear arms treaty between Russia and the United States could collapse unless Washington ratifies it before next month's elections change the Senate's composition, a senior Russian lawmaker said.

The signing of the new START treaty in April was a step towards U.S. President Barack Obama's goal of "resetting" relations with the Kremlin, so its derailment would be a big setback for the White House's foreign policy agenda.

The treaty is not in force until it has been ratified by legislatures in both countries and Konstantin Kosachyov, chairman of the international affairs committee in Russia's lower house of parliament, said this now hung in the balance.

The Kremlin ally said he remained hopeful that the Senate could ratify the treaty in the so-called lame duck session, when it re-convenes after the Nov. 2 congressional elections but before newly elected senators take up their seats.

"If for whatever reason -- political, technical -- that does not happen ... then I think the agreement will have problems from the point of view of ratification, very big problems," Kosachyov told Reuters in an interview late on Saturday.

The agreement will cut strategic nuclear arsenals deployed by the former Cold War foes by 30 percent within seven years but leave each with enough to destroy the other. Its predecessor treaty expired in December last year.

"WORSE CASE SCENARIO"

Kosachyov said if Republicans made big gains in the Senate in next month's election, as many opinion polls suggest, it would not be possible to garner the two-thirds vote needed to ratify the new treaty.

"Many (Republican Senators) will be in principle against agreeing on anything with Russia. In that case we will have to start from scratch. That is the worst case scenario. Completely awful. For now I do not want to believe in it," he said.

"For now I am disappointed with how all this is going but I am optimistic because there are very good chances that it will be ratified in the lame duck session," Kosachyov said on the sidelines of the World Policy Conference in Morocco.

But he said: "If it (the treaty) collapses just because of internal political considerations of the United States, that would be very bad."

Some Republican senators say they worry the new treaty may limit U.S. missile defences, and some want Obama to promise to spend more money modernizing the nuclear weapons that remain.

Russian President Dmitry Medvedev has submitted the treaty to Russia's parliament, but he told lawmakers not to ratify the agreement before the full U.S. Senate has approved it. (Editing by Mark Trevelyan)