(Jim Lo Scalzo/EPA)

A key Republican has shifted his stance on a landmark vote to defund the NSA's collection of telephone metadata. In a letter to House leadership Tuesday, Rep. Darrell Issa (R-Calif.) urged another vote on Rep. Justin Amash's (R- Wis Mich.) legislative language that would have curtailed the program charged with gathering bulk phone records.

"Now that the House is back in session," the letter reads, "I respectfully request that you move legislation to the floor, including language of the Amash Amendment that was narrowly defeated on July 26, 2013, during debate on the Department of Defense Appropriations Act, as quickly as possible."

Issa, chairman of the House Oversight Committee, had previously sided against Amash's amendment in a 217-205 vote. The close outcome led civil liberties advocates to claim that major changes on surveillance were afoot in Washington.

While President Obama has mostly defended the NSA's surveillance activity, he hinted last week that new laws may be necessary to keep up with the technology that has enabled the snooping. Speaking to reporters in Sweden, Obama admitted that the "risks of abuse are greater than they have been in the past." And though the five-person panel appointed by the administration to review the NSA's programs is sorely lacking in technologists, the group met yesterday with over a dozen public interest groups to discuss the agency's missteps, according to the Office of the Director of National Intelligence.

House Majority Leader Eric Cantor (R-Va.) must now decide whether to bring Amash's amendment back to the floor. If he refuses, expect the pressure to grow.