WASHINGTON—Senator Elizabeth Warren says she is throwing “my full support” behind the re-election bid of her Massachusetts Democratic colleague Ed Markey in an endorsement video to be released by his campaign on Monday

The 90-second video, which follows a public endorsement by Warren in February, comes as Representative Joseph P. Kennedy III is considering a primary challenge against Markey, potentially triggering a divisive intraparty fight at a time when Democrats are grappling with a rising insurgency calling for fresher and more diverse faces in Congress.

Calling him a friend, fighter and true progressive, Warren says in the video shot late last week that Markey is needed in the Senate “now more than ever,” citing his leading track record on climate change, and a career spent “as our country’s greatest champion for clean energy jobs and as Big Oil’s worst nightmare.”


“Ed is my friend and my partner in the Senate,” she says, looking straight into the camera. “I’ve got his back, and I know that he will always have yours. Let’s get Ed Markey reelected to the Senate.”

Markey, 73, a Malden native, was elected to the Senate in 2013. He has been a fixture of Massachusetts politics since he first won a House seat in the suburbs north of Boston in 1976. He faces at least two candidates in the Democratic primary, labor attorney Shannon Liss-Riordan and businessman and author Steve Pemberton.

But a challenge from Kennedy, the grandson of Senator Robert F. Kennedy, would be formidable. He will decide whether to challenge Markey in the coming weeks, according to a person close to Kennedy.

Warren has opted to stay above the fray in other Democratic primary battles. Over the weekend, she expressed kind words for Markey and Kennedy in a brief interview with a New York Times reporter.


“Eddie has been a great partner in the Senate,” she said. But then she also said Kennedy — who along with his wife was a former student — also has been a great partner and is “really an amazing person.”

Markey and Kennedy have endorsed Warren’s bid for the Democratic presidential nomination.

Markey said in a statement Monday that he was “proud” to have Warren’s endorsement, calling her a “great friend and partner.”

Reach Jazmine Ulloa at jazmine.ulloa@globe.com or on Twitter: @jazmineulloa