House Speaker John Boehner
House Speaker John BoehnerReuters

In announcing the controversial Iran nuclear deal on Tuesday, US President Barack Obama threatened to "veto any legislation" blocking the deal, leading senior Senators to speculate as to the prospects that the 60-day review period and subsequent vote on the deal will have a chance of stopping it.

Republicans in the Senate will need to muster 60 votes in order to pass the legislation, technically known as a resolution of disapproval, that would block Obama from lifting sanctions against Iran, the world's leading state sponsor of terrorism, reports Associated Press. However, since Republicans hold only 54 seats in the Senate, six Democrats will be needed to achieve the goal.  

The resolution of disapproval would need only the support of the Republican majority to pass the House. 

If the resolution is passed and Obama vetoes it, opponents of the Iran deal will need a two-thirds majority in both the Senate and the House of Representatives to overrule the veto. This means Obama needs only 34 Democrats to support him in the Senate, for the veto to be sustained. 

"I think he's going to be working hard to get 34 votes," Senate Majority Leader Mitch McConnell (R-KY) said. He added that it would be "hard" to overcome Obama's veto threat.

Also weighing in on the prospects was Senator Dianne Feinstein (D-CA), a Democrat close to Obama, who said "I just don't think" two-thirds of the Senate will be gathered to shoot down Obama's veto.

Congress has 60 days to review the deal, during which time the sanctions against the Islamic regime cannot be lifted.

Senator Bob Corker (R-TN), chairman of the Senate Foreign Relations Committee, warned against supporting the deal, saying, "Iran continues to be the lead sponsor of terrorism in the world and relieving sanctions would make the Tehran regime flush with cash and could create a more dangerous threat to the United States and its allies."

"We will do everything to stop it"

Calling for opposition to the deal, House Speaker John Boehner (R-OH) said, "if in fact it is as bad of a deal as I think it is at this moment, we will do everything we can to stop it."

"It's going to hand a dangerous regime billions of dollars in sanctions relief while paving the way for a nuclear Iran," he said. "Instead of stopping the spread of nuclear weapons in the Middle East, this deal is likely to fuel a nuclear arms race around the world.”

In an appeal for unity against the deal, the House Speaker added, "this isn’t about Republicans versus Democrats. It’s about right and wrong. And we will fight a bad deal that is wrong for our national security and wrong for our country."

"At the outset of these talks, the Obama administration said it would secure an agreement that affirmed Iran does not have a right to enrich and permanently dismantles the infrastructure of its nuclear programs. It said that sanctions would not be lifted until Iran met concrete, verifiable standards. And if these terms were not met, the president promised he would walk away."

"The American people and our allies were counting on President Obama to keep his word. Instead, the president has abandoned his own goals," concluded Boehner, noting the massive concessions on core principles included in the deal.

Effect on the presidential elections

Even after the 60-day review period ends and a vote is taken, the issue of the Iran nuclear deal will apparently remain a fiercely debated topic in America, and will likely be a central focus in the 2016 presidential election.

Democratic candidate Hillary Clinton, who formerly served as Obama's secretary of state, has backed the deal as an "important step."

She has claimed the deal will end up "putting the lid on Iran's nuclear program," even though it does not dismantle any of Iran's nuclear facilities or destroy any centrifuges.

Republican candidates are expected to vigorously oppose the Iran deal.

One Republican presidential candidate, Wisconsin Governor Scott Walker, made clear that "Iran's Supreme Leader should know that a future American president will not be bound by this diplomatic retreat."