A treaty governing the high seas is all but dead in the Senate as two Republican senators announced their opposition Monday, giving conservative foes the necessary votes to scuttle the pact.

Sens. Rob Portman of Ohio and Kelly Ayotte of New Hampshire -- both mentioned as possible running mates for likely Republican presidential nominee Mitt Romney -- said they had serious concerns about the breadth and ambiguity of the Law of the Sea treaty and would oppose it if called up for a vote.

The Constitution requires two-thirds of the Senate -- 67 votes -- to ratify a treaty; Portman and Ayotte bring the number of opponents to 34 along with Sens. Mike Johanns, R-Neb., and Johnny Isakson, R-Ga.

The development was a blow to the Obama administration, military leaders and the business community led by the U.S. Chamber of Commerce, who had argued that the treaty would improve national security and enhance U.S. standing in the world. They had pressed for ratification of the treaty, which was concluded in 1982 and has been in force since 1994. The United States is the only major nation that has refused to sign the pact.

Sen. Jim DeMint, R-S.C., and other conservatives have led the campaign against the treaty, contending that it would undermine U.S. sovereignty. DeMint heralded the latest development on Twitter, saying, "34 Senators now oppose LOST, sinking the misguided treaty."
The treaty establishes a system for resolving disputes in international waters and recognizes sovereign rights over a country's continental shelf out to 200 nautical miles and beyond if the country can provide evidence to substantiate its claims. The United States has abided by the rules of the treaty since President Ronald Reagan's administration.

Secretary of State Hillary Rodham Clinton had told Congress in May that the treaty could be a boon to business as U.S. oil and natural gas companies now have the technology to explore the extended continental shelf, which could be more than 1 1/2 times the size of Texas and rich in resources.
But Portman and Ayotte were not swayed.

"Proponents of the Law of the Sea treaty aspire to admirable goals, including codifying the U.S. Navy's navigational rights and defining American economic interests in valuable offshore resources," the two said in a letter to Senate Majority Leader Harry Reid, D-Nev. "But the treaty's terms reach well beyond those good intentions. This agreement is striking in both the breadth of activities it regulates and the ambiguity of obligations it creates. "

The two also raised concerns about authorization of international and judicial entities. "The United States would be binding itself to yet-unknown requirements and liabilities. That uncertainty alone is reason for caution," Portman and Ayotte wrote.

Senate Foreign Relations Committee Chairman John Kerry, D-Mass., has tried to build a case for ratification of the treaty, with a vote planned for the lame-duck session after the November elections. He was steadfast Monday in his commitment to the treaty despite the growing opposition.

"Senator Kerry has been here long enough to know that vote counts and letters are just a snapshot of where our politics are in this instant, and it's not news to anyone that right now we're in the middle of a white hot political campaign season where ideology is running in overdrive," said spokeswoman Jodi Seth in a statement. "No letter or whip count changes the fact that rock-ribbed Republican businesses and the military and every living Republican secretary of state say that this needs to happen, and that's why it's a matter of `when' not `if' for the Law of the Sea."

Kerry had a series of hearings with star witnesses, starting with Clinton, Defense Secretary Leon Panetta and Army Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, making a rare joint appearance. Four admirals, including the chief of naval operations and the vice chairman of the Joint Chiefs of Staff, and two generals also urged senators to support the treaty. And last month, business leaders, including the head of the Chamber, testified on behalf of the pact.
But the conservative opposition was too formidable.

Heritage Action, which lobbied against the treaty, said in a statement from CEO Michael A. Needham: "America had little to gain through accession to the Law of the Sea Treaty -- but much to lose. Rather than affirming existing practices, it would have instituted a radically new, international legal regime. The demise of the Law of the Sea Treaty not only represents a victory for American sovereignty, but also the American people."