Three days after House Republicans grilled Interior Department officials for allowing what they called camping in McPherson Square, the National Park Service is threatening eviction for some Occupy DC protesters in Freedom Plaza.

Park Service officials began passing out fliers today to protesters who have been living in McPherson Square and Freedom Plaza since September. They have until noon-time Monday to dismantle tents or other “temporary structures.”

“This communication serves as notice that … the United States Park Police will commence enforcement of the long-standing National Park Service regulations that prohibit camping and the use of temporary structures for camping in McPherson Square and Freedom Plaza,” the flier reads.

“If camping violations are observed, individual violators may be subject to arrest and their property subject to seizure as evidence,” the flier continues. “Any temporary structure used for camping will also be subject to seizure as abatement of a public nuisance.”

Defining camping as “sleeping or preparing to sleep,” the Park Service will enforce rules against tents and structures erected for sleeping.

However, “24/7 demonstration vigils and the use of symbolic temporary structures, including empty tents as symbols of the demonstration, may be permitted in the park areas.”

Residents of both parks are “occupying” the spaces as offshoots of the Occupy Wall Street movement.

At an Oversight and Government Reform subcommittee hearing Tuesday, Republicans accused Park Service Director Jonathan Jarvis of being selective in his enforcement of park regulations. They argued that camping, not allowed in federal parks, has been taking place in McPherson Square.

The Park Service conceded that camping activities have been taking place but said by and large the protesters are protected by First Amendment rights to assemble. Democrats on the panel agreed with that assessment.

Jarvis said Tuesday that his department would begin, at some time in the near future, to crack down on camping, but he said that short of an emergency the protesters would not be evicted. The Park Police’s actions on Monday will be the first step in seeing whether it will be possible to draw a distinction between “camping” and a “24-hour vigil.”

Oversight and Government Reform Chairman Darrell Issa (R-Calif.) issued a statement today expressing support for the development.

“The Park Service’s decision to begin enforcing the law is appropriate and overdue,” he said. “The laws on camping were carefully crafted to meet with Supreme Court jurisprudence, and a continued failure to enforce them would have undermined the First Amendment.”

Rep. Trey Gowdy (R-S.C.), chairman of the panel’s Subcommittee on Health Care, District of Columbia, Census and the National Archives, told Roll Call that he could not speculate what effect Tuesday’s hearing might have had on forcing Jarvis’ hand in starting enforcement activities.

“I want to be fair to Mr. Jarvis,” Gowdy said. “He may have had this in mind irrespective of the hearing. Among my many limitations is the inability to read other people’s minds or motives.”

Whatever the motivation, Gowdy said, he is pleased with the development.

“The prohibition is against camping, and that necessarily requires you to define what camping is, and there I’m sure is a legal distinction between a 24-hour vigil and camping, and my concern is to make sure that people who have different ideological bents are treated the same,” he said. “To me, it’s as simple as: If you’re going to have a regulation or a rule, apply it.”