(Bloomberg) -- Almost 300 renewable power developers and manufacturers are appealing to congressional leaders to advance the climate provisions in President Joe Biden’s tax-and-spending plan, warning that major clean-energy projects hang in the balance. 

“Each month of delay means an estimated $2 billion in lost economic activity,” the more than 260 companies said in a letter to Senate Majority Leader Chuck Schumer and House Speaker Nancy Pelosi. “The clean energy initiatives represent a once-in-a-generation opportunity for Congress to take big, bold action to deliver the clean energy future Americans want and deserve.”

The push by the American Clean Power association and companies representing hundreds of billions of dollars in market value comes as Democrats weigh the best approach for advancing Biden’s plan, now stalled amid objections from Democratic senators Joe Manchin of West Virginia and Kyrsten Sinema of Arizona. 

While the companies stopped short of explicitly asking Schumer and Pelosi to spin off the measure’s roughly $555 billion in climate and clean-energy provisions, Biden last week endorsed breaking up the package. 

The legislation’s climate measures include more than $300 billion in new and expanded tax credits for wind and solar power, nuclear plants, biofuels and advanced energy manufacturing. 

The provisions are estimated to more than double clean energy investment to $750 billion over the next 10 years, potentially helping the U.S. deploy 750 gigawatts of wind, solar and battery storage by the end of the decade, said the letter signers, including Avangrid Inc., Dominion Energy Inc., NextEra Energy Inc., Orsted A/S and Schneider Electric SE. 

It’s critical that those measures take effect retroactively to Jan. 1, 2022 to realize their full potential, they said. 

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