Senator Corker warns of 'erosion' on Iran deal

The influential chairman of the Senate Foreign Relations Committee, Bob Corker, is worried that the US is ceding too much in its negotiations with Iran.

So worried that he's suggesting the US pull out of the deal if what he calls "the erosion" continues. He is particularly concerned about the inspections clauses in the deal. He says he's hearing (though when I pushed him he wouldn't say from whom) that the right to inspections of Iran's nuclear facilities anytime, anywhere, may be diluted.

He also points to redlines that have already been crossed, highlighting the fact that the deal has gone from being a 20-year agreement to a 10-year agreement, and that Iran's nuclear arrangements can be dismantled in country, not out of country.

Mr Corker told me he still wants a deal, and sees that as the best option for America. But the man who guided the Senate to a bill that gave overwhelming support the negotiations now sounds more sceptical.