US President Barack Obama has almost enough support from senators to block Republican attempts to derail a deal with Iran over its nuclear programme.

On Tuesday, two more Democratic senators came out in favour of the deal giving the White House 33 votes in favour of it, one vote shy of what is needed to make any attempts to kill it nearly impossible.

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The deal, which was officially reached July 14 in Vienna between Iran and the so-called P5 plus one countries (the US, Russia, China, the UK, France, and Germany), would lift decades-old sanctions on Iran in exchange for Tehran's promise not to develop nuclear weapons.

The US Congress which is set to debate it when they return from their summer break next week and must vote on the deal by September 17.

Senator Bob Casey of Pennsylvania and Chris Coons of Delaware said on Tuesday they believe it is a deal worth supporting in spite of their own scepticism that Iran will hold up its end of the bargain.

"Frankly, this is not the agreement I had hoped for," said Coons. But if the US Congress rejects it, "the path forward is even less clear", he added.

Although the US Congress is currently controlled by the Republican Party, who are overwhelmingly against the agreement, one-third of US senators (34 votes) can block any attempts to reject it clearing a path for its approval.

Meanwhile, a new poll shows US citizens are almost evenly divided on the deal with 55 percent saying they support it.

Source: Al Jazeera