Tensions are rising in Michigan’s Republican gubernatorial race, as one of the frontrunners, Tudor Dixon, on Friday issued a cease-and-desist letter to opponent Kevin Rinke, demanding he take down an ad accusing her of taking millions from opponents of former President Donald Trump.

Dixon’s attorneys sent the order over Rinke’s “Can’t Trust Tudor” commercial, which claims “establishment Republicans like Tudor Dixon will say anything to get President Trump’s support, then betray him when it matters most.”

“She claims to be for Trump, but she’s been endorsed by the RINO establishment’s leading Never-Trumpers,” the ad states. “Worse, Tudor Dixon has taken millions from the same billionaires who tried to remove Trump from office.”

That is an apparent reference to the powerful DeVos family of west Michigan, who have endorsed Dixon, a Norton Shores conservative media personality and former steel industry executive.

Betsy DeVos, former U.S. Secretary of Education, recently acknowledged she and other Cabinet members discussed invoking the 25th Amendment to remove Trump from office after his supporters stormed the U.S. Capitol to try to block his election loss on Jan. 6, 2021.

Campaign finance reports are not due until next week, and the cease-and-desist letter to Rinke notes that Michigan campaign finance laws prohibit any candidate from accepting contributions that are more than $7,150 from an individual donor.

The letter warns of “impending litigation” over the ad.

“Campaigns can be tough, and we understand the frustration that must come with failing at fundraising, spending millions of your own dollars, and not getting traction with voters,” reads the letter to Rinke, a millionaire who is helping fund his own campaign.

“Your own sinking boat does not, however, give you license to publish malicious lies.”

Trump has publicly praised Dixon but has not yet endorsed in the race. Rinke has also aired a separate ad comparing himself to Trump.

Rinke, a Bloomfield Township businessman, defended his ad at a media conference following a GOP gubernatorial debate on Friday, saying Dixon “pandered to President Trump and misrepresented her loyalties.”

“And at the end of the day, all I wanted in my ad was to tell the truth. You can’t have it both ways,” Rinke told the media on Friday. “I think the president needed to know that Tudor was saying one thing and doing another thing.”

Katie Martin, Rinke’s spokesperson, told Bridge Michigan on Friday that Dixon is “being exposed for trying to deceive Trump all while being bankrolled by the folks who tried to remove him from the White House.”

Fred Wszolek, who runs Michigan Strong, a super PAC backing Dixon, tweeted on Friday that Rinke’s ad is “a desperate move by the highest-spending candidate in the race, who is on the verge of finishing fourth.”

There are five candidates in the Aug. 2 primary to determine who faces Democratic incumbent Gov. Gretchen Whitmer in the general election.

Polls have shown different frontrunners, but a recent one by Mitchell Communications Research and commissioned by MIRS claimed Dixon has an 11 percentage point lead over the other GOP candidates with 26 percent of the vote.