WASHINGTON — An Internet travel writer who was leaked an airline security directive asked the Transportation Security Administration today to postpone enforcement of a subpoena so he could challenge it in federal court.

Chris Elliott said TSA agents showed up at his house, demanding that he reveal who leaked the security directive that followed a Christmas Day attack on a Detroit-bound airliner. The directive included security measures that quickly became apparent to many travelers.

The administrative subpoena — a demand for information issued without a judge's approval — will be challenged next week in federal court in Orlando, Fla., said Lucy Dalglish, executive director of the Reporters Committee for Freedom of the Press. Dalglish said she was acting as Elliott's spokesman on the issue.

TSA and its parent agency, the Department of Homeland Security, had no immediate comment today.

Another travel blogger who received a subpoena, Steve Frischling, said he met with two TSA special agents Dec. 29 at his Connecticut home for about three hours and again Dec. 30 when he was forced to hand over his laptop computer.

Frischling said the agents threatened to interfere with his contract to write a blog for KLM Royal Dutch Airlines if he didn't cooperate and provide the name of the person who leaked the memo.

Dalglish said she was not speaking for Frischling, but added there was nothing to challenge if he had already handed over his computer. She said she could not remember the last time an administrative subpoena had been served on a reporter in last decade.

"They should seriously reconsider this," Daglish said. "Millions of fliers know these rules are out there."

The TSA directive outlined new screening measures that went into effect the same day as the airliner incident at Detroit. It included many procedures that would be apparent to the traveling public, such as screening at boarding gates, patting down the upper legs and torso, physically inspecting all travelers' belongings, looking carefully at syringes with powders and liquids, requiring that passengers remain in their seats one hour before landing, and disabling all onboard communications systems, including what is provided by the airline.

It also listed people who would be exempted from these screening procedures, such as heads of state and their families.