update: 3:23 p.m. with statement of support from President Obama, plans for Congressional hearings from House Republicans.

The Federal Communications Commission voted Tuesday to approve its first ever Internet access regulation, which ensures unimpeded access to any legal Web content for home Internet users.

The FCC's three Democratic members made up a majority of votes in favor of the so-called net neutrality regulation, which was introduced more than a year ago by FCC Chairman Julius Genachowski.

The rules have sparked intense debate and lobbying over whether such legislation is needed, and are likely to face a legal challenge. Genachowski has argued that Internet access rules would protect companies just starting out on the Web, as well as consumers who are increasingly relying on the Internet for news, entertainment and communications.

The agency's two Republican members voted against the rules, showing support for Internet service providers who say the regulations will impede their ability to create new business plans to expand their broadband networks and boost speed.

Genachowski said the measure represents a compromise between industry and consumer interests.

"I reject both extremes in favor of a strong and sensible framework -- one that protects Internet freedom and openness and promotes robust innovation and investment," Genachowski said.

The same provisions do not apply as strongly to cellphone users because the agency voted to keep wireless networks generally free of rules preventing the blocking and slowing of Web traffic.

The net neutrality measure is the federal government's first move to regulate broadband access. Questions remain, however, over whether the agency has the legal right to serve as the nation's watchdog over Internet access. Last spring, a federal appeals court said the FCC overstepped its authority by sanctioning Comcast for blocking access to users of BitTorrent's peer-to-peer sharing application.

The rules are sure to face a court challenge and have prompted opposition from Republican lawmakers, who plan to tackle the regulation through Congressional action.

Reps. Fred Upton (R-Mich.) and Greg Walden (R-Ore.) said they would summon Genachowski for hearings on whether the agency has authority to pursue such rules. They, along with Rep. Marsha Blackburn (R-Tenn.), said the move was a "power grab" and that legislation would be introduced to overthrow the regulations. Sen. Kay Bailey Hutchison (R-Tex.) said she will move to withdraw funds appropriated to the FCC to execute the rules.

"We are going to be exploring every option to reverse this order. This will be one of our first hearings we will embark on in the next Congress," said Upton, incoming chairman of the powerful Energy and Commerce Committee.

And on the other side, consumer groups aren't happy, either. Public interest groups have said they will consider filing suit against the rules that they fought to enact, asserting that the regulation doesn't go far enough to protect consumers.

"We asked for three changes, primarily that rules governing wireless services be strengthened," said Gigi Sohn, president of consumer advocacy group Public Knowledge. "The changes would have made the FCC’s action much stronger without disturbing the framework Chairman Genachowski put forward. It is unfortunate he chose not to adopt them."

Democratic commissioners Michael J. Copps and Mignon Clyburn agreed that the rules fell short but said they were willing to back the government's first step toward overseeing Internet access.

Copps said he considered opposing the measure but instead chose between the better of two bad options: weak rules or no rules at all. He said the FCC should redefine broadband as a telecom service to protect the regulations from constant court battles. The FCC is considering such a proposal by Genachowski.

"To be clear, we do not anchor ourselves on what I believe to be the best legal framework," Copps said. "Nor have we crafted rules as strong as I would have liked. But, with today’s action, we do nonetheless appear to steer ourselves back toward a better course."

The vote's success fulfills a promise that Genachowski made at the start of his tenure in fall 2009 to preserve open Internet access.

President Obama issued a statement in support of the new regulations:

Today’s decision will help preserve the free and open nature of the Internet while encouraging innovation, protecting consumer choice, and defending free speech. Throughout this process, parties on all sides of this issue – from consumer groups to technology companies to broadband providers – came together to make their voices heard. This decision is an important component of our overall strategy to advance American innovation, economic growth and job creation.