WASHINGTON — U.S. Rep. Mike Coffman on Thursday demanded that a major Democratic booster stop sending Colorado voters an attack piece about him because he says the political mailer inaccurately describes his stance — or lack thereof — on Donald Trump.

Specifically, Coffman is disputing the flier’s assertion that he supports the Republican presidential nominee. Coffman, R-Aurora, is running for re-election in a swing district that curls east around Denver, and he has made a point of not saying either way whether he backs Trump — which is why his attorney sent a cease-and-desist letter to the House Majority PAC, a super PAC that backs Democratic House candidates.

The mailer makes the claim that “Mike Coffman Supports Donald Trump And That Puts America’s Safety At Risk,” according to a copy included in the correspondence.

“The advertisement includes false statements prohibited by Colorado law,” notes attorney Jonathan Anderson in a letter to the House Majority PAC. “Mike Coffman has never indicated that he supports Donald Trump as a candidate for President.”

Coffman made national headlines this summer when he released a TV ad that took issue with Trump. “People ask me, ‘What do you think about Trump?’ Honestly, I don’t care for him much,” Coffman says in the ad.

He’s running this year against Democrat Morgan Carroll, who has spent much of her campaign trying to link together the two Republicans. Colorado’s 6th Congressional District is about one-fifth Latino, and Democrats often have contrasted Trump’s harsh rhetoric toward immigrants and Latinos with Coffman’s past legislative positions.

Coffman previously supported legislation that would make English the official language, but he since has tried to learn Spanish — even dueling Democratic rival Andrew Romanoff in a Spanish-language debate during their 2014 battle.

For much of the 2016 election, Coffman has said Trump still needs to earn his vote. Asked when Coffman planned to make a decision, spokeswoman Cinamon Watson said it would come soon.

“He plans on watching the debates and making a decision when ballots go out,” Watson said.

She called the House Majority PAC mailer an example of “sleazy election year tricks.”

A spokesman for House Majority PAC defended the flier, and noted a past statement by a Coffman aide who said the congressman “obviously” would support the Republican candidate over a Democrat. That was long before Trump clinched the nomination, however.

“We haven’t yet received a letter from Congressman Coffman or his campaign, however, we take Mr. Coffman’s spokesperson at her word when she said he would ‘obviously’ support the Republican nominee for President, which Mr. Coffman hasn’t denied,” said Jeb Fain of the House Majority PAC.