BOSTON (CBS/AP) – Democratic Rep. Joe Kennedy III has made his decision – he will run against Sen. Ed Markey in the upcoming Massachusetts primary race.

Kennedy will announce his plans during an event Saturday in East Boston, a source close to Kennedy told WBZ-TV political analyst Jon Keller.

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The 38-year-old grandson of Robert Kennedy has been weighing a decision for several weeks.

Keller sat down with Kennedy earlier this month, and the congressman said he was “working through” his plans.

“It’s a big decision, for me, for my family, but there’s also the question of how you’re gonna be received across the state,” Kennedy said.

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The 73-year-old Markey said he spoke with Kennedy Wednesday and is looking forward to the campaign.

“Elections are about choices, and Ed looks forward to spending the next 14 months campaigning hard every day to show the people of the Commonwealth why he’s the right choice,” Markey’s campaign said in a statement.

Rep. Joe Kennedy III (left) and Senator Edward Markey. (Photo by Darren McCollester/Getty Images)

A Kennedy-Markey duel could put more than a few high-profile Democrats in an awkward position — most notably Democratic presidential candidate Elizabeth Warren.

Warren has worked with Markey in the Senate and taught Kennedy at Harvard Law School. She has formally endorsed Markey.

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