Fully half of the US Senate has now signed on as co-sponsors of the “Nuclear Weapons Free Iran Act of 2013,” a bill that aims to violate the P5+1 interim deal by imposing new sanctions on Iran, effectively ending chances for a diplomatic rapprochement.

The bill, first introduced by Senate hawks before Christmas, not only aims to impose sanctions but also expresses US support for any Israeli military attack on Iran at any time in the future.

President Obama has threatened to veto the bill, saying he wants to keep diplomacy going for the time being, and the White House says the veto plan remains in effect.

With 50 sponsors though, the Senate hawks seem to be moving close to a veto-proof majority in the Senate, meaning they could sabotage the P5+1 talks even without the president’s permission.