By Louis Charbonneau
UNITED NATIONS (Reuters) - The leaders of Britain, France and Germany on Thursday defended the Iran nuclear deal agreed in July between Iran and major powers as the debate in U.S. Congress heated up due to fierce opposition to the agreement among Republican lawmakers.
Under the July 14 agreement, sanctions on Iran will be lifted in exchange for at least a decade of curbs on Tehran's nuclear programme, which Western powers and their allies fear has been a cover for Tehran to acquire the capability to produce atomic weapons. Iran denies that allegation.
British Prime Minister David Cameron, French President Francois Hollande and German Chancellor Angela Merkel vigorously defended the agreement in an article published in the Washington Post.
"The U.S. Congress is voting this week on whether to support the agreement," the European leaders said. "This is an important moment. It is a crucial opportunity at a time of heightened global uncertainty to show what diplomacy can achieve."
"Two years of tough, detailed negotiation have produced an agreement that closes off all possible routes to an Iranian nuclear weapon in return for phased relief from nuclear-related sanctions," they said.
Republican critics of the deal say U.S. President Barack Obama's administration gave Iran too much in exchange for too little in the negotiations. They also say that it will enable Iran to become a nuclear weapon state once the restrictions on its uranium enrichment programme lapse.
Despite the fact that Republicans control both houses of the U.S. legislature, Obama has enough support to sustain a veto over any attempts to block the deal. Under a law Obama signed in May, Congress has until Sept. 17 to try to pass a resolution disapproving of the deal.
Republicans have vowed to continue fighting the deal, even though they appear to have virtually no ability to block its implementation.
"This is not an agreement based on trust or on any assumption about how Iran may look in 10 or 15 years," the leaders wrote. "Iran will have strong incentives not to cheat: The near certainty of getting caught and the consequences that would follow would make this a losing option."
Sanctions on Iran are to be reimposed if it violates the agreement.
"We are confident that the agreement provides the foundation for resolving the conflict on Iran's nuclear programme permanently," the three said. "This is why we now want to embark on the full implementation of the (deal) once all national procedures are complete."