If Congress votes to disapprove, and a presidential veto follows, Congress will have to hold another vote on whether to override the veto, which requires two-thirds majority in both chambers.

The following are the key numbers to watch for when Congress votes:

First round: 218 votes required in the House to pass a resolution of disapproval (or approval); 60 votes required in the Senate to overcome a procedural hurdle before voting on the actual resolution, which would then require 51 votes to pass.

Second round: If Congress passes a resolution of disapproval, it will go to President Obama who has said he will veto it.

Third round: Congress will then have 10 days to hold a vote to override President Obama’s veto. A congressional veto override requires 290 House votes and 67 Senate votes.​ Which means the president would need 146 House votes or 34 Senate votes to sustain his veto and allow for approval of the deal, assuming all members vote.

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Last update: September 15 at 6:00 p.m. ET

Senate				House
42 Support	58 Oppose	0 Undeclared		163 Support	270 Oppose	1 Undeclared

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