Any updates to FERC’s more than 20-year-old policy statement on natural gas pipeline reviews should not apply to projects that have already submitted applications to the agency, according to a bipartisan group of U.S. Senators.

In a letter to the Federal Energy Regulatory Commission Thursday, the lawmakers called on the agency “to take action without further delay” on the natural gas infrastructure projects currently pending.

The letter was signed by 25 senators, a list comprising mostly Republicans along with Democratic Sen. Joe Manchin (D-WV), Kyrsten Sinema (D-AZ) and Jon Tester (D-MT).

FERC in February initiated a notice of inquiry process to revisit its 1999 policy statement guiding its evaluation of the interstate natural gas infrastructure projects under its...