Rep. Joe Kennedy III of Massachusetts will announce his bid for Senate this weekend, sources told NBC10 Boston.
Kennedy will formally announce his primary campaign against Sen. Ed Markey, a fellow Democrat, sources said. The Boston Globe first reported the story, saying that the announcement would come in East Boston.
The four-term representative confirmed last month that he was eyeing the Senate seat, but he said he had not made a final decision.
"I'm thinking about what I have to offer Massachusetts voters, what is most important in this political moment, and what kind of party Democrats need to be building for the future," he said in a Facebook post on Aug. 26.
Soon after, Kennedy elaborated on why he was considering the primary run.
"Sen. Markey is a good man," he said in Newton last month. "I think I've got new ideas and a new approach, and if I get into this race, that's what this race will be about."
Kennedy, the 38-year-old grandson of late Sen. Robert F. Kennedy, has represented Massachusetts' 4th Congressional District since 2013. Markey, 73, has been the state's junior U.S. senator since the same year.
Markey's campaign confirmed that he and Kennedy spoke Wednesday.
"In 2013, Ed Markey asked voters to send him to the U.S. Senate to fight for the people of Massachusetts," John Walsh, a senior campaign advisor, said in a statement. "Since then, he has fought on the front lines to show them they were right. Now he wants to continue that leadership on the issues that matter most -- climate change, income inequality, gun reform, universal health care, reproductive freedom, and immigrant rights."
The two lawmakers share similar policies. While Kennedy's youth figures to be a factor, Markey has received the endorsement of Rep. Alexandria Ocasio-Cortez, D-N.Y., with whom he partnered on the Green New Deal climate change proposal.
Massachusetts' other U.S. Senator, Democrat Elizabeth Warren, has spoken highly of both men.
"I endorsed Sen. Markey back in February. I couldn't ask for a better partner in the Senate than Ed Markey. He is a good friend," she said. "Joe Kennedy is also a good friend. I have worked with him since he was a student of mine; both he and his wife were my students. I have worked with him as a congressman. I have nothing but the highest respect for him."
The Kennedy family is one of the most prominent political dynasties in the U.S. — the representative's grandfather was seeking the Democratic presidential nomination when he was assassinated, and his great uncle, John F. Kennedy, served in the Senate before being elected president. It has been 10 years since a Kennedy served in the Senate — Ted Kennedy, another great uncle of Joe Kennedy III, died in 2009.