WASHINGTON — Republicans in the Senate picked Pennsylvania Sen. Pat Toomey to be their voice on Iran Wednesday during the weekly GOP address.

He asked Americans to call their senators and representatives to urge them to oppose the deal.

“What’s at stake here is nothing less than the possibility of giving hundreds of billions of dollars to the world’s largest and worst state sponsor of terrorism, and ultimately paving the way for this outlaw regime to obtain nuclear weapons,” Toomey said in the recorded address. “This deal is very dangerous.”

Supporters of the deal, including Sen. Bob Casey, D-Pa., and U.S. Rep. Mike Doyle, D-Forest Hills, say the agreement is imperfect but that it will constrain Iran’s ability to build nuclear weapons and that Iran is unlikely to agree to a more stringent accord.

Wednesday was Toomey’s fourth time delivering the weekly Republican address.