Donald Trump, Jr. speaks during a rally with President Donald Trump at the Williamsport Regional Airport in Montoursville, Pa., on Monday, May 20, 2019.

Donald Trump Jr. is planning to campaign against the only Republican congressman who has called for the president's impeachment.

Donald Trump Jr. will be heading to Michigan to fight Rep. Justin Amash in a primary battle, people close to the Trump Organization executive told CNBC, speaking on the condition of anonymity. This comes after Trump's son tweeted out a poll showing Amash losing to his only challenger so far in the race, state legislator Jim Lower, and hinting he will be heading to the Wolverine state to take on the four-term lawmaker.

"See you soon Justin... I hear Michigan is beautiful during primary season," Trump Jr. said.

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Trump Jr.'s associates also said he will not be involved with recruiting any of the potential primary challengers for Michigan's 3rd Congressional District, which is in the western part of the state and includes Battle Creek, and will leave that task up to Republican Party leaders.

Amash responded to the possibility of Trump Jr. working the primary by saying: "If it's what you say I love it especially later in the summer."

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An Amash spokeswoman referred CNBC to his tweet and a representative for Trump Jr. declined to comment.

Tensions between Amash and Republicans loyal to President Donald Trump came to a boiling point after the Michigan representative reviewed the Mueller report and declared on Twitter that the president engaged in impeachable conduct.