oFlorida Governor Ron DeSantis speaks in Manchester
Florida Governor Ron DeSantis acknowledges the audience after speaking at the 2023 NHGOP Amos Tuck Dinner in Manchester, New Hampshire, U.S., April 14, 2023. Reuters

A fundraising group supporting Florida Governor Ron DeSantis's potential run for U.S. president on Sunday launched its first attacks on leading rival Donald Trump, questioning the former president's allegiance to his fellow Republicans.

"Trump should fight Democrats, not lie about Governor DeSantis," the ad stated. "What happened to Donald Trump?"

Former president Trump launched a bid for the 2024 Republican nomination in November and polls show he is leading the field of declared and as-yet undeclared candidates. DeSantis, who is expected to launch a run, is in second position in polls.

Never Back Down, the Super PAC backing DeSantis, released the ad titled "Fight Democrats, not Republicans" online and on "Fox News Sunday."

The ad begins with a reference to Trump's legal troubles in New York.

"Donald Trump has been attacked by a Democrat prosecutor in New York. So why is he spending millions attacking the Republican governor of Florida?"

Trump pleaded not guilty in Manhattan on April 4 to 34 felony counts of falsifying business records related to a hush-money payment made to porn star Stormy Daniels. He was questioned on Thursday in a separate $250 million business fraud lawsuit brought by the state's attorney general.

Make American Great Again, the major Super PAC aligned with Trump, has already attacked DeSantis in ads.

Its latest release on Friday referenced a Daily Beast report that DeSantis ate chocolate pudding with his fingers while on a flight from Tallahassee to Washington in 2019.

"DeSantis has his dirty fingers all over senior entitlements, like cutting Medicare, slashing Social Security, even raising our retirement age," the ad said. "Tell Ron DeSantis to keep his pudding fingers off our money."