Washington CNN  — 

The architect of a measure that would give Congress more oversight over President Barack Obama’s nuclear deal with Iran says he’s skeptical the Middle Eastern country would live up to its agreements.

Senate Foreign Relations Committee Chairman Bob Corker, R-Tennessee, on Sunday told CNN’s Jim Sciutto on “State of the Union” that he’s afraid the United States and five other world powers involved in the negotiations have given away too much to Iran in their effort to strike a deal.

READ: Is Congress sabotaging a nuclear deal with Iran?

And, he said, he’s afraid Iran’s negotiators have been kept in the dark about the country’s ambitions to build a nuclear weapon — given so little information that they “could pass a lie detector test.”

“We’re concerned that if the negotiators don’t even know on behalf of Iran all the things Iran has been doing, how are we going to know?” Corker said.

Still, Corker and Maryland Democratic Sen. Ben Cardin, the top Democrat on the Senate Foreign Relations Committee, pitched legislation they hashed out that would give Congress a 52-day window to reject the deal — which would phase out Western sanctions in exchange for a drop in Iranian centrifuges and more inspections — saying it’s the best chance for Congress to thoroughly vet the deal.

“Right now, the leadership in Iran is telling their citizens one thing. Our President is telling us another,” Corker said, adding that lawmakers want to see what’s in the classified annex once negotiators have worked out a final text ahead of a June 30 deadline.

The Senate could soon vote on the Corker and Cardin measure, which the foreign relations panel approved last week.

Cardin was more optimistic about the Iran negotiations than Corker, but stressed that the measure isn’t tantamount to a vote on the final deal.

“It is not a vote on the merits of the agreement. We don’t know what’s in that agreement until we see it in June,” he said.