The US senator Joe Manchin released an energy permitting bill on Wednesday to speed up fossil fuel and clean energy projects.

The bill is expected to be attached to a measure to temporarily fund the government that Congress must pass before 1 October.

The legislation would require the federal government to issue permits for Equitrans Midstream Corp’s long-delayed $6.6bn Mountain Valley Pipeline to take natural gas between West Virginia, Manchin’s home state, and Virginia.

The wider funding bill needs approval of the House and Senate and to be signed by Joe Biden to become law. Manchin’s staff told reporters that he believed the funding bill will would get the 60 votes needed to pass the Senate with the permitting measure attached.

The permitting measure from Manchin, a centrist Democrat and an important swing vote in the 50-50 Senate, would require Biden to designate 25 energy projects of strategic national importance for speedy federal review.

The USelectricity grid needs expansion and fixes as some of its major transmission lines are 50 years old. Improving transmission lines would help renewable projects like wind and solar farms in rural areas get clean power to cities.

The bill also sets a two-year target for environmental reviews on energy projects that need to be completed by more than one federal agency.

Progressive lawmakers and environmental groups have been concerned that the bill would speed fossil fuel projects while undermining US environmental laws. In the House of Representatives, 77 Democrats this month asked the House speaker, Nancy Pelosi, to keep the side deal out of the funding bill.

Senator Tim Kaine, a Democrat from Virginia, said after the bill was released he could not support its “highly unusual provisions” regarding Mountain Valley pipeline.

Kaine said they “eliminate any judicial review” for key parts of the pipeline approval process and strip jurisdiction away from a US court of appeals for cases involving it. He said he had not been included in talks about the measure, even though 100 miles (160 km) of the pipeline would run through his state.

While the bill would speed up the processes required by a bedrock US green law called the National Environmental Policy Act, which mandates reviews of major projects, “it doesn’t amend the underlying statutes”, a member of Manchin’s staff told reporters in a call.

Getting at least 10 Republican senators to support the measure could be complicated after Senator Shelley Moore Capito, a Republican from Manchin’s state, issued her own bill this month more favorable to fossil fuels.

Some Republicans were also concerned because Manchin voted for Biden’s Inflation Reduction Act, which contained $369 bn for climate and energy security.

Speaking about the unwillingness of some Republicans to support permitting, Manchin said on Tuesday: “If they’re willing to say they’re going to shut down the government because of a personal attack on me, or by not looking at the good of the country, that is what makes people sick about politics.”