A terrorism defendant and federal prosecutors are clashing over the constitutionality of warrantless surveillance in a closely watched case.

After taking back his plea that he had aided terrorists by emailing and sending money to an alleged Pakistani extremist, Agron Hasbajrami insists any evidence collected through previously undisclosed warrantless monitoring must be suppressed.

The Albanian native, who is a lawful permanent resident, asserts that a 2008 law amending the Foreign Intelligence Surveillance Act to allow warrantless wiretaps runs afoul of constitutional prohibitions against unreasonable government intrusions. Prosecutors needed a warrant to build their case against him, Hasbajrami said.