(CNN) In January, the USA Freedom Kids rocketed to viral fame after performing at a Donald Trump rally in Pensacola, Florida. But undisclosed after the red, white and blue performance of "Freedom's call" was a brewing resentment from the group's manager toward the Trump campaign.

This behind-the-scenes disagreement has now boiled over into the threat of a lawsuit, as first reported by The Washington Post.

Jeff Popick, the father of one of the girls and manager of the group, confirmed to CNN on Tuesday he soon intends to file a suit against the Trump campaign and said he had secured the legal services of lawyer Marc Shapiro.

"It's not going to be a billion dollar lawsuit," Popick stressed, calling the impetus for the suit mostly an issue of "morality."

Popick said the disagreement stemmed from two broken promises the Trump campaign made to the USA Freedom Kids. He said the Trump campaign did not honor an agreement to let the group set up a table to sell its CDs at a rally and then canceled a performance without explanation in Des Moines, Iowa, after the group made a "very lengthy odyssey" to do a set at a Trump event.

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