Senator Mikulski
Democratic senator Barbara Mikulski, known as the longest serving female senator in history, announced her support for the deal on Wednesday (2 September)Reuters

US President Barack Obama officially received the 34 votes in the Senate to overrule a possible Republican-led resolution against his nuclear deal with Iran. Democratic senator Barbara Mikulski, the longest-serving female senator in history, announced her support for the deal on 2 September.

Her support means Obama has 34 senator votes in favour, allowing him to sustain a veto in case the Republicans decide to launch a congressional resolution to disapprove of the deal. Mikulski stated she thought the deal was far from perfect but said: "I have concluded that this Joint Comprehensive Plan of Action is the best option available to block Iran from having a nuclear bomb. For these reasons, I will vote in favour of this deal."

She did warn that it was now up to the US Congress to make sure there is a significant commitment to the safety and security of Israel.

The deal with Iran, which was announced on 14 July, was historic for the Persian country, and would see international sanctions lifted in exchange for the promise that it will significantly reduce its nuclear programme.

The deadline for a congressional resolution of disapproval is 17 September. Although Republicans hold the majority of seats in both Congress and the Senate, Obama has vowed his dedication to the deal, saying he would try to overrule any such efforts.

Mikulski, who was one of 11 undecided democratic senators before 2 September, said: "It's unclear if the European Union, Russia, China, India and others would continue sanctions if Congress rejects this deal. At best, sanctions would be porous, or limited to unilateral sanctions by the US."

On 1 September, senators Bob Casey and Chris Coons announced their support for the deal, just a week before democrats in the Senate and the White House hope to delay a resolution of disapproval by holding a filibuster.