The office of Senator Joe Manchin III of West Virginia said that he secured a promise from Democratic leaders and the White House to complete a 304-mile gas line in his state.

Mr. Manchin made the easing of permits for energy projects a requirement of the deal. On Tuesday, his office made public details of the side agreement he struck with a number of people.

It would make sure that federal agencies take all necessary actions to allow the construction and operation of the gas line. The project, which has been opposed for years by environmentalists, civil rights activists and many Democratic state lawmakers in Virginia, would carry natural gas from West Virginia to Virginia.

Environmental groups have successfully challenged a number of federal permits for the project in the United States Court of Appeals for the Fourth District in Virginia.

The permits issued by the Fish and Wildlife Service, the Bureau of Land Management and the Forest Service were found to be flawed by the court.

The project will not be certified by the Federal Energy Regulatory Commission in October. The developers are trying to get another extension.

The ability of Congress to move the project forward is acknowledged by a senior attorney for the Center for Biological Diversity. He said that a challenge from opponents would not be prevented.

The United States Court of Appeals for the District of Columbia Circuit would take the case away from the Fourth District because of the side deal cut by Mr. Manchin.

Sign up for the Climate Forward newsletter, for Times subscribers only.  Your must-read guide to the climate crisis.

The agreement makes it harder for opponents to hold up energy projects by setting a two-year time limit for challenges. Fossil fuels and nuclear energy must be included in 25 priority projects on federal lands. It would change a section of the Clean Water Act to make it harder to block or delay a project.

Neither of them responded to questions. The White House spokesman didn't reply.

Ral Grijalva, the chairman of the House Committee on Natural Resources, is one of the Democrats who said they wouldn't support fast-track projects.

Three people familiar with Mr. Manchin's agreement said Democratic leaders were likely to insert permitting provisions into a must-pass piece of legislation, such as the bill that funds the federal government.

Mr. Manchin believes the United States needs to change the rules around permits to increase energy production.

We're asking people to do what we want to do for ourselves. Mr. Manchin spoke. How do we get a permitting process that will allow us to meet the challenges that we have today and the need that we can't do because of our permitting?

ImageJoe Manchin wears a suit and walks in a Congressional hallway.
Senator Joe Manchin III also won concessions that require the president to establish several fossil fuel “priority” projects.Credit...Sarahbeth Maney/The New York Times
Joe Manchin wears a suit and walks in a Congressional hallway.

The agreement with Mr. Manchin was denounced by environmental activists.

As Congress is poised to accelerate the development of energy projects, the implications of this side deal are very important. She was worried that developers could run roughshod over communities if they limited the time to review and challenge projects.

The creation of a new pipeline would cause more greenhouse gas emissions into the future according to the opponents. Natural gas is expected to be delivered more than two billion times a day.

The environmental groups did not call for lawmakers to vote against the climate and tax package. The package will reduce emissions by as much as 40 percent by the end of the decade, even though Mr. Manchin was able to get some measures for fossil fuel development.

The permitting deal was called a victory by some.

Neil Chatterjee was the former chairman of the Federal Energy Regulatory Commission.

Making it easier to get permits for projects could help add wind, solar and other renewable energy to the electrical grid quicker.

The climate and tax bill is expected to be voted on this week, according to Mr. Schumer.