5:00 PM PT -- Joey Chestnut tweeted an hour ago reacting to the news, saying "I was gutted to learn from the media that after 19 years Im banned from the Nathan's July 4th Hot Dog Eating Contest"

"I love competing in that event, I love celebrating America with my fans all over this great country on the 4th and I have been training to defend my title."

"To set the record straight, I do not have a contract with MLE or Nathans and they are looking to change the rules from past years as it relates to other partners I can work with. This is apparently the basis on which I’m being banned, and it doesn’t impact the July 4th event."

"Sadly, this is the decision Nathan's and Major League Eating are making, and it will deprive the great fans of the holiday’s usual joy and entertainment. To my fans, I love you and appreciate you.  Rest assured that you’ll see me eat again soon!! STAY HUNGRY!"

This is a doggone shame.

Joey Chestnut -- the world's greatest eater -- will not defend his mustard belt at the Nathan's Hot Dog contest this year ... and it's all the result of a sponsorship deal he inked with a rival company.

According to the NY Post, Chestnut recently joined forces with Impossible Foods to promote its new plant-based alternative to tube steaks ... which created major issues with organizers and the governing body -- Major League Eating.

A rep for MLE told the outlet it tried like hell to reach an agreement that would satisfy both sides ... but ultimately, there was no way to make it work.

"We are devastated to learn that Joey Chestnut has chosen to represent a rival brand that sells plant-based hot dogs rather than competing in the 2024 Nathan’s Famous Fourth of July Hot Dog Eating Contest," MLE said in a statement.

"MLE and Nathan's went to great lengths to accommodate Joey and his management team, agreeing to the appearance fee and allowing Joey to compete in a rival, unbranded hot dog eating contest on Labor Day."

It's a major blow for the yearly Fourth of July tradition ... as Chestnut has won the competition 16 times in his career -- including each contest since 2016. He holds the current world record for glizzys guzzled with 76 in 2021.

"For nearly two decades we have worked under the same basic hot dog exclusivity provisions," the org added. "However, it seems that Joey and his managers have prioritized a new partnership with a different  brand over our long-time relationship."

The bridge isn't burned forever, though -- MLE said it hopes to welcome the "American hero" back to the contest at a future date ... when he's no longer in bed with a rival brand.

It's another blow for the competitive eating community -- as we previously reported, Takeru Kobayashi announced his retirement from the sport earlier this year.

Pour some ketchup out for this one.