Elon Musk Calls President Biden 'Damp Sock Puppet' Over Auto Industry Diss

The tension between Elon Musk and President Joe Biden is on the rise again ... with the billionaire hurling new, and colorful, insults over a perceived White House diss.

Elon was once again not invited to a summit meeting on Thursday, where top leaders – including Ford and GM's CEOs – are working together to promote Biden's "Build Back Better" bill.

The Prez gave them high marks for producing electric vehicles ... which Elon, Mr. Tesla himself, clearly took as a direct shot.

Musk lashed out on Twitter, saying ... "Biden is treating the American public like fools" -- and, for good measure, he called the President "a damp [sock] puppet in human form."

No response from the White House. Ditto for Lamb Chop.

This also happened last year after an electric vehicle White House summit in August. If you're wondering why Elon's being shut out ... WH Press Secretary Jen Psaki said back then, "The 3 largest employers of the United Auto Workers" had been invited. Yeah, it's because Tesla's factories are not unionized.

Elon's racking up opponents in DC -- you'll recall he's also been in a war of words with Sen. Elizabeth Warren, who's railed on him for not paying enough income tax ... in her eyes.

Elon fired back, "You remind me of when I was a kid and my friend's angry Mom would just randomly yell at everyone for no reason."