John Fetterman is turning up the heat on his fellow Democrat — and challenging Michigan Senate nominee Abdul El-Sayed to take his far-left alliances to the general election.

In a blunt interview with The Washington Post, the Pennsylvania senator warned that El-Sayed has put a seat Democrats desperately need to hold in play, while taking direct aim at the Michigan Democrat’s campaign, his opposition to military aid for Israel and his willingness to campaign alongside far-left streamer Hasan Piker.

“He has put, you know, that seat in play,” Fetterman said.

Fetterman then unloaded on the forces behind El-Sayed’s nomination, arguing that Bernie Sanders and other progressives have repeatedly pushed candidates who could create serious problems for Democrats in competitive states.

“And after Bernie Sanders and others created the disaster in Maine, and they pushed garbage person like Platner, and now they’ve pushed an individual like El-Sayed that’s been very proud of his very deeply anti-Israel views and proud to campaign with an avowed communist overall,” Fetterman said.

The stakes are hardly small.

Michigan is among roughly a dozen Senate contests expected to help determine which party controls the chamber. El-Sayed defeated establishment-backed Rep. Haley Stevens in a Democratic primary that attracted more than $80 million in spending — the most expensive Democratic Senate nomination contest in history.

Now El-Sayed will face former Republican Rep. Mike Rogers for the seat being vacated by retiring Democratic Sen. Gary Peters.

And Fetterman wants to know whether El-Sayed is prepared to bring the same politics that won the Democratic primary into a general election where far more voters will be watching.

That question becomes especially pointed when it comes to Piker.

The far-left streamer repeatedly appeared with El-Sayed during the campaign, including at a Detroit pool party on the eve of the primary. Piker has previously made controversial remarks about the United States and praised Mao Zedong as “one of the great leaders of this world.”

El-Sayed has said he does not share all of Piker’s positions. But he has also resisted demands that he distance himself from the streamer.

Fetterman is essentially daring him to keep it that way.

“I dare you to continue to campaign with people like Hasan Piker because he now will quickly find out it’s easy to campaign in the echo chamber as a Democrat,” Fetterman said.

That may be the real test for El-Sayed.

Winning a Democratic primary is one thing. Taking the same message to Michigan voters in a general election is another.

The Republican National Committee has already seized on the relationship, accusing Democrats of refusing to confront El-Sayed’s political associations.

“Democrats’ refusal to disavow this clown shows they either share his poisonous ideology or they’re too cowardly to confront it,” RNC National Spokesperson Natalie Baldassarre told Fox News Digital.

The Democratic establishment is hardly united behind El-Sayed, either. Peters endorsed Stevens during the primary, although he has since predicted that El-Sayed will defeat Rogers by focusing on issues affecting Michigan families.

But the feud became even more personal when The Washington Post played Fetterman a clip of El-Sayed criticizing his approach to Midwestern politics and his temperament.

Fetterman responded by accusing El-Sayed of bringing what he described as “little man syndrome energy.”

And that may be the most revealing part of this Democratic family fight.

The party that spent years insisting its progressive candidates represented the future now has one of its own senators publicly warning that the movement may have nominated someone too far to the left for a critical swing state.

El-Sayed won the primary. Now comes the harder part: convincing Michigan voters that the politics, rhetoric and alliances that worked inside the Democratic echo chamber belong in the U.S. Senate.

Fetterman has thrown down the challenge. Keep campaigning with Piker. Keep defending the radical associations. Keep running the primary-election playbook.

Michigan voters will get the final say.