Across the country, activists with ties to the Tea Party are railing against all sorts of local and state efforts to control sprawl and conserve energy. They brand government action for things like expanding public transportation routes and preserving open space as part of a United Nations-led conspiracy to deny property rights and herd citizens toward cities.

They are showing up at planning meetings to denounce bike lanes on public streets and smart meters on home appliances — efforts they equate to a big-government blueprint against individual rights.

"Down the road, this data will be used against you," warned one speaker at a recent Roanoke County, Va., Board of Supervisors meeting who turned out with dozens of people opposed to the county’s paying $1,200 in dues to a nonprofit that consults on sustainability issues.

Local officials say they would dismiss such notions except that the growing and often heated protests are having an effect.

In Maine, the Tea Party-backed Republican governor canceled a project to ease congestion along the Route 1 corridor after protesters complained it was part of the U.N. plot. Similar opposition helped doom a high-speed train line in Florida. And more than a dozen cities, towns and counties, under new pressure, have cut off financing for a program that offers expertise on how to measure and cut carbon emissions.

"It sounds a little on the weird side, but we’ve found we ignore it at our own peril," said George Homewood, a vice president of the American Planning Association’s chapter in Virginia.

The protests date to 1992 when the United Nations passed a sweeping, but nonbinding, 100-plus-page resolution called Agenda 21 that was designed to encourage nations to use fewer resources and conserve open land by steering development to already dense areas. They have gained momentum in the last two years because of the emergence of the Tea Party movement, harnessing its suspicion about government power and belief that man-made global warming is a hoax.

In January, the Republican Party adopted its own resolution against what it called "the destructive and insidious nature" of Agenda 21. And Newt Gingrich took aim at it during a Republican debate in November.

Tom DeWeese, the founder of the American Policy Center, a Warrenton, Va.-based foundation that advocates limited government, says he has been a leader in the opposition to Agenda 21 since 1992. Until 2010, he had few join his efforts beyond a handful of farmers and ranchers in rural areas. Now, he is a regular speaker at Tea Party events.

Membership is rising, DeWeese said, because what he sees as tangible Agenda 21-inspired controls on water and energy use are intruding into everyday life. "People may be acting out at some of these meetings, and I do not condone that. But their elected representatives are not listening, and they are frustrated."

Fox News has also helped spread the message. In June, after President Barack Obama signed an executive order creating a White House Rural Council to "enhance federal engagement with rural communities," Fox programs linked the order to Agenda 21. A Fox commentator, Eric Bolling, said the council sounded "eerily similar to a U.N. plan called Agenda 21, where a centralized planning agency would be responsible for oversight into all areas of our lives. A one world order."

The movement has been particularly effective in Tea Party strongholds like Virginia, Florida and Texas, but the police have been called in to contain protests in states including Maryland and California, where opponents are fighting laws passed in recent years to encourage development around public transportation hubs and dense areas in an effort to save money and preserve rural communities.

One group has become a particular target. Iclei — Local Governments for Sustainability USA, an Oakland, Calif.-based nonprofit, sells software and offers advice to communities looking to reduce their carbon footprints. A City Council meeting in Missoula, Mont., in December got out of hand and required police intervention over $1,200 in dues to Iclei.

At a Board of Supervisors meeting in Roanoke in late January, Cher McCoy, a Tea Party member from nearby Lexington, Va., generated sustained applause when she warned: "They get you hooked, and then Agenda 21 takes over. Your rights are stripped one by one."

Echoing other protesters, McCoy identified smart meters, devices being installed by utility companies to collect information on energy use, as part of the conspiracy. "The real job of smart meters is to spy on you and control you — when you can and cannot use electrical appliances," she said.

Ilana Preuss, vice president of Smart Growth America, a national coalition of nonprofits that supports economic development while conserving open spaces and farmland, said, "The real danger is not that they will get rid of some piece of software from Iclei" but that "people will be too scared to have a conversation about local development. And that is an important conversation to be having."

In some cases, the protests have not been large, but they are powerful because officials are concerned about the Tea Party.

On the campaign trail, Gingrich has called Agenda 21 an important issue and has said, "I would explicitly repudiate what Obama has done on Agenda 21."

The Republican National Committee resolution, passed without fanfare on Jan. 13, declared, "The United Nations Agenda 21 plan of radical so-called ‘sustainable development’ views the American way of life of private property ownership, single family homes, private car ownership and individual travel choices, and privately owned farms; all as destructive to the environment."

Other conservatives have welcomed the scrutiny of land-use issues, but they do not agree with the emphasis on Agenda 21.

Jeremy Rabkin, a professor of law at George Mason University specializing in sovereignty issues, said there were "entirely legitimate concerns about international standards that come into American law without formal ratification by the Senate."

But some local officials argue that the programs that protesters see as part of the conspiracy are entirely created by local governments with the express intent of saving money — the central goal of the Tea Party movement.

Planning groups, several of which said they had never heard of Agenda 21 until protesters burst in, are counter-organizing.

Summer Frederick, the project manager for the Thomas Jefferson Planning District Commission in Charlottesville, Va., which withdrew its dues to Iclei and its support from a national mayors’ agreement on climate change late last year after a campaign by protesters, now conducts seminars on how to deal with Agenda 21 critics. (Among her tips: Remove the podium and microphones, which can make it "very easy for a critic to hijack a meeting.")

Roanoke’s Board of Supervisors voted 3-2 to renew its Iclei financing after many residents voiced their support.

"The Tea Party people say they want non-polluted air and clean water and everything we promote and support, but they also say it’s a communist movement," said Charlotte Moore, a supervisor who voted yes. "I really don’t understand what they want."

© 2012 The New York Times Company