Corporate tax changes proposed in President Joe Biden’s $2 trillion spending plan threaten to undercut his ambitious climate goals and undermine clean-power development, according to energy companies that oppose it.

The latest version of the spending package, which is still being debated in the U.S. Congress, includes a minimum tax of 15% on a corporation’s book income. That would sharply diminish the benefits of other financial incentives in the legislation designed to hasten the build-out of green power, the American Clean Power Association said in a letter to Senate leaders and seen by Bloomberg News.