DENVER (AP) — Two Western members of the Senate Intelligence Committee don’t believe that the federal government’s telephone surveillance has stopped terrorist attacks.

Sen. Mark Udall of Colorado and Sen. Ron Wyden of Oregon issued a joint statement Friday saying that they “respectfully but firmly” disagree with the way senior White House officials have described the program.

“After years of review, we believe statements that this very broad Patriot Act collection have been a ‘critical tool in protecting the nation’ do not appear to hold up under close scrutiny,” the Democratic senators said, referring to a comment from White House spokesman Josh Earnest in defense of the effort.

Leaders of Congress’ intelligence panels also say the program recently helped thwart what would have been a significant domestic terrorist attack.

But Udall and Wyden say they’re not convinced the surveillance has provided any “uniquely valuable intelligence.” They think all the useful information that’s been collected could have been obtained in other ways that don’t violate people’s privacy.

Udall told The Denver Post on Thursday that he was aware the federal government was broadly monitoring Americans’ telephone and email communications and “tried everything short of leaking classified information”, including threatening to hold up confirmations, to try to bring attention to the issue.

Last year, the first-term Democrat tried unsuccessfully to get the National Security Agency director to estimate how many Americans have had their communications monitored.

Udall wouldn’t say whether he knew about the scope of the surveillance at the time.

“I think the most important thing to focus on right now is that the administration made commitments to being transparent,” Udall told the newspaper. “President Obama said he was going to submit to transparency in the State of the Union. I expect him to uphold his commitment.”

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