National Park Service (NPS) Director Jonathan Jarvis said law enforcement will “very soon” begin to enforce anti-camping regulations against Occupy protesters in Washington, D.C.’s McPherson Square in what could signal a change in the generally peaceful relationship between the agency and the movement.

Jarvis, testifying at a congressional hearing, said protesters at the federally-controlled park in downtown Washington will get “one more warning” before enforcement begins. He didn't provide an exact date of when that may happen.

Since September, the agency has allowed the group to protest by day and sleep at night in the park. Authorities have taken a less aggressive approach to policing the protesters than in many other cities, and they've avoided the violent confrontations that dominated the news last year.

But the National Parks Service's laissez-faire policy has come at a cost: city officials are growing increasingly concerned with the potential for health and safety problems that will only be exacerbated as temperatures drop. Dealing with the fallout will be the city's health agency, even though it was the federal government -- not the city government -- that has made the decision to let the protesters remain.

That dynamic caused an unusual alliance between the city leaders – who typically resent any type of Congressional oversight – and Republican lawmakers on the oversight committee who are also questioning the National Parks Service's handling of the situation.

Jarvis came under the thumb of Republicans at an oversight subcommittee hearing this morning. They accused his agency of neglecting its law-enforcement duties and suggested that administration officials, sympathetic to the Occupy cause, had instructed him not to remove the protesters.

NPS prohibits camping in McPherson Square, yet Jarvis conceded the protesters have been allowed to camp there, and none of them have faced criminal penalty for it. U.S. Park Police haven’t enforced the no-camping rule because officials don't want to risk inciting a reaction. He also described the delicate legal issues at stake: although camping in the park is illegal, 24-hour-a-day protesting is not. In the case of Occupy, those two issues are intricately related.

He also said his agency's delicate response is not unprecedented. In 1979, 6,000 farmers protested at the National Mall for seven weeks to protest farm policy. After Martin Luther King, Jr. was killed in 1968, a month-long vigil was held in D.C.

Republicans wouldn’t have any of it. “You are, in fact, turning a blind eye to four months of law-breaking,” House Oversight Committee Chairman Darrell Issa, R-Calif. He and other Republicans said the agency has set a dangerous precedent and opened the door to future protesters -- or tourists, for that matter -- demanding the right to camp indefinitely on federal land in the District of Columbia.

They also say NPS is setting a double-standard if it ignored no-camping rules for protesters in the District of Columbia, but enforces them against citizens visiting parks elsewhere in the country. Rep. Joe Walsh, R-Ill., repeatedly suggested NPS was being influenced by the administration. “Who’s telling you not to enforce the statute?” Walsh asked Jarvis. “Why aren’t you enforcing that law? It’s been four months. Are there some sort of political sensitivities?”

Jarvis, for his part, said he wasn't being influenced and he doesn't care about the protesters' politics. “My job … is to protect the individuals’ rights under the First Amendment.”

Issa also made the case that the District was paying the price for the agency's inaction. A memo from the city’s health director last month said it’s “only a matter of time” before disease, hypothermia, and foodborne illness break out in the McPherson Square encampment, which is infested with rodents and lacks refrigerated food and hot water. The issue reached a boiling point Jan. 11 when a 13-month-girl was found abandoned in a tent at the park. Protesters said the man charged with abandoning her were not associated with their group.

In December, D.C. Mayor Vincent Gray wrote a letter to NPS requesting that it reimburse the city for more than $1.6 million in expenses associated with the protesters, including sanitation work, park and street maintenance and law enforcement overtime. He also expressed his frustration that the NPS didn’t consult with city leaders before making the choice to allow the long-term camping.“Our citizens cannot be expected to pay for the consequences of a decision in which they have no say,” Gray says.

Gray has requested that, at a minimum, that the McPherson Square encampment -- which typically has about 25 to 50 protesters -- be merged with another a second Occupy protest site that is cleaner and better organized. The second site, Freedom Plaza, is located about five blocks from McPherson Square on federal land across the street from City Hall.

In a rare moment of dissent with her mayor, Rep. Eleanor Holmes Norton suggested the questions about reimbursement are moot, since there are already federal funds set aside to reimburse the city for expenses associated with protests. Norton – a former First Amendment attorney – joined other Democrats in drawing parallels between the Occupy protests and the civil rights movement. They highlighted the District's unique place in the country as the epicenter of protests that have had long-lasting impacts.

The protesters themselves weren’t invited to testify. In a statement they provided the committee, they said they’re happy to work with both NPS and the city to improve the health and safety conditions of the camp. "Citizens of a free country shout not have to ask for permission to occupy public spaces," the group said in a statement.