This is NO Food fight as TV’s top food divas wage all-out culinary combat for the hearts and stomachs of America!

act like friends in public and even appear on each other’s shows, but sources tell The ENQUIRER that behind the scenes they’re more like mortal enemies.

The taste-making trio are locked in a brutal battle of the brands – fighting for TV ratings, sales of their magazines and cookbooks, as well as buyers for their vast array of products.

"Martha, Rachael and Paula are in a crowded market, and they’re competing for each other’s audience," a TV source tells The ENQUIRER.

"Each one of them wants desperately to be number one, and they’re in a dogfight that’s gotten down and dirty!"

Sources say the vicious war of words between Martha, 69, Rachael, 42, and Paula, 63, has recently sunk to appalling lows.

According to insiders, both Martha and Rachael think Paula is a "hillbilly," Martha has cracked that Rachael is a "drunk," and Rachael has joked that given the chance, she’d love to "slap" Martha!

Meanwhile, Paula – a Food Network darling who’s sold more than eight million books – has plans to crush them both, sources say.

But Martha – whose company Martha Stewart Living Omnimedia Inc. posted a loss last year – won’t go down without a fight, according to insiders.

In a bid to spur sales of her magazine, housewares, paint, bedding, furniture and other branded products, she’s gone into overdrive, providing the Hallmark Channel with a whopping eight hours of programming each weekday.

"From 10 a.m. to 6 p.m., Hallmark essentially becomes the Martha Stewart Network," said an insider.

Rachael is very envious over Martha’s Hallmark deal, according to sources, and she’s still smarting over how Martha treated her when she appeared on her show in November 2009.

"While Martha was gracious to Rachael, she craftily proceeded to make mincemeat out of her by exploiting her weaknesses, especially getting Rachael to admit that she can’t bake," said another source.

"Martha delivered a near-steady barrage of subtle digs at Rachael, who looked really uncomfortable."

A vindictive Martha – who has business deals with Macy’s, Home Depot, Kodak, PetSmart and more – has also taken digs at her younger rival’s drinking, sources say.

"When there were published reports that Rachael may have made racist comments about Oprah when she had too much to drink one night, Martha laughed, ‘Rachael is a drunk,’" said an insider close to Martha.

With an empire of her own – including the magazine Every Day with Rachael Ray, several Food Network shows, an Emmy-winning daytime show and branded products – Rachael hasn’t hesitated to lash back at Martha, sources say.

"The nasty gossip Martha spreads has gotten back to Rachael – and Rachael dishes about Martha in return. It’s a vicious cycle between them," said a source close to Rachael.

"Rachael has even cracked, ‘I’d love to slap Martha!’"

Rachael is just as determined to stay on top of her silver-haired rival Paula.

"She thinks Paula is a ‘hillbilly’ who cooks with unhealthy ingredients and serves up fried, fatty foods."

Like Rachael, Martha disses Paula’s dishes, sources say.

"Martha can’t stand what Paula makes. She says it’s just fat-laden comfort food with no aspiration toward art in the kitchen," divulged an insider close to Martha.

"She says Paula is going to turn America into a nation of obese housewives! Martha has even laughed that Paula is a hillbilly."

But insiders say that sniping doesn’t bother Paula, who calls herself "America’s Most Popular Chef," and is busy building her own empire.

A two-time Emmy winner, she headlines the Food Network’s top-rated shows – Paula’s Home Cooking, Paula’s Party and Paula’s Best Dishes. Her magazine, Cooking with Paula Deen, has a circulation of more than one million.

"Paula harbors no personal resentment against Rachael or Martha, but she’s a competitor, and her popularity is growing," said an insider.

"She definitely wants to be number one, and if that happens, it’ll crush Martha and Rachael in the process."