A federal judge expressed interest in advancing a lawsuit that challenges the constitutionality of the National Security Agency’s mass surveillance program.

U.S. District Judge Richard J. Leon laid out a strategy on Wednesday after the U.S. Court of Appeals for the District of Columbia Circuit lifted his December 2013 injunction blocking the NSA program on Friday.

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The NSA’s massive surveillance program, which collects Americans’ phone records, was ruled illegal in May by a federal appeals court, on the basis that the NSA’s broad collection “exceeds the scope of what Congress has authorized.”

During a hearing on Wednesday, Leon encouraged conservative lawyer Larry Klayman, who initially brought the suit against the NSA, to amend his case to include customers of Verizon Business Network Services as well as ask a federal appeals court to dismiss an appeal on the case. Leon also noted the past ruling in which the appeals court found the NSA’s program illegal.

[quote_center]“This court has ruled. This court believes that tens of millions of Americans’ constitutional rights have been — and are being — violated,” Leon said. “If the court finds jurisdiction, I don’t have to write another opinion on the merits… It is written.”[/quote_center]

Section 215 of the Patriot Act, which was used to justify the NSA’s data collection, expired on June 1, and after debate as to whether the U.S. government should have any kind of surveillance program collecting data from innocent Americans, it was replaced by the USA Freedom Act.

Although the USA Freedom Act was presented as a law that would end the NSA’s data collection by putting bulk records into the hands of telephone companies, the Department of Justice filed a request asking the Foreign Intelligence Surveillance Court to continue the NSA’s collection for six months.

[RELATED: DoJ Asks Surveillance Court To Ignore Federal Court’s Ruling On Illegal NSA Spying]

The FISA Court approved the federal government’s request on June 29, reauthorizing NSA data collection through Nov. 29, 2015.

The upcoming due date is one that Leon mentioned during the hearing. He told Klayman that it is critical to move now due to the limited time window between now and November.

“The clock is running and there isn’t much time between now and November 29,” Leon said. “This court believes there are millions and millions of Americans whose constitutional rights have been and are being violated, but the window for action is very small – it’s time to move.”