Joe Biden has committed a “strategic mistake” by “bear-hugging” the Israeli prime minister, Benjamin Netanyahu, as he prosecutes war with Hamas, a leading congressional progressive Democrat and Biden campaign surrogate said.

“The bear-hugging of Netanyahu has been a strategic mistake,” Ro Khanna said, accusing the Israeli leader of conducting “a callous war” in Gaza, in defiance of the United States.

Speaking to One Decision, a podcast co-hosted by Sir Richard Dearlove, a former British intelligence chief, Khanna, from California, also called Netanyahu “insufferably arrogant”, for acting as if he is “somehow an equal” to Biden.

But his comments about Biden’s mistakes may land with a thud at the White House.

Liz Landers, a One Decision guest host, asked Khanna about a recent trip to Michigan to meet leaders of the state’s large Arab American community.

“What did they tell you about the Biden administration’s policy with Israel?” Landers asked.

“They were opposed,” Khanna said, adding: “I’ve been a longtime supporter of the US-Israel relationship. I’ve been in Congress eight years and my record reflects that I unequivocally condemned the brutal Hamas attack [on Israel] on 7 October, the rapes, the murders. I’ve called Hamas a terrorist organisation, which obviously they are.

“They committed a terrorist act on 7 October, but the bear-hugging of Netanyahu has been a strategic mistake. Netanyahu has conducted a callous war in defiance of the United States.

“I did not support a ceasefire for the first six weeks. I thought [Israel] would go and get the people responsible [for the 7 October attacks]. But they started bombing refugee camps, bombing hospitals, defying the United States and not letting aid in.”

Biden, Khanna said, needed to set out “clear consequences for Netanyahu” if Israel does not change course.

“He needs to say, ‘I’m for Israel, but I’m not for this extreme rightwing government.’ And that means if [Netanyahu] defies the United States, not allowing aid, or going into Rafah” – which Biden has said must not happen but Netanyahu has said will – “[then] no more weapons transfers … unconditionally.

“It means not protecting [Netanyahu] from the entire international community at the United Nations, it means recognising a Palestinian state. And those are the things I think some of the Arab American community want.”

Asked about a looming clash over Rafah, Khanna highlighted Netanyahu’s behaviour, refusing to heed Biden’s warning that the attack would represent a “red line”.

“What I disagree with and sort of the media narrative on this [is that] Netanyahu and Biden, somehow they’re equals,” Khanna said.

“They’re not. We’re the greatest superpower in the world. We’re giving Netanyahu weapons. He needs to be deferential with respect to the American president, whoever that is. And I find it insufferably arrogant for him to act as if he’s somehow an equal to the American president. And that’s just going to rub people the wrong way.

“So if he defies the American secretary of defense, the American president, then we should stop the arms shipments now. We can stop the offensive arms shipments … I voted for defensive funding and we need to continue to protect Israel against an invasion from Hezbollah or Iran. But we certainly shouldn’t be giving Netanyahu the offensive weapons to go kill more people in Gaza when he’s acting in defiance to the president of the United States.

“You can act as an equal if you’re not begging for weapons at the same time.”

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On Thursday morning, Khanna commented further.

“I respect the people and state of Israel, the Palestinian people and believe all nations are equal in self determination,” the congressman said on social media.

“But Bill Clinton said 28 years ago that Netanyahu failed to respect America’s leadership and power and disregarded our views despite our strong support.”

Biden’s Israel policy has also had an effect in domestic politics, protest votes in Democratic primaries sounding a warning for the presidential election to come. Landers asked Khanna if Biden could lose his re-election fight against Donald Trump because of such protests as seen in Michigan, where about 100,000 voted “uncommitted”.

Khanna said: “I think the president’s gonna win. I mean, he won Michigan [by] almost 150,000 votes.”

But he said anger with Biden was spreading “probably beyond the Muslim or Arab American community. It’s more young people, voters of colour, the broader Democratic coalition.

“And I think if this war continues, particularly if it’s continuing when we head to the Democratic convention in Chicago, then it creates a problem for us with the coalition that Barack Obama built, which was young people, progressives, voters of colour, that really turned out.”

Khanna said there was potential for the convention, in mid-August, to generate unwelcome echoes of chaos in Chicago in 1968, the year of an election won by the Republican Richard Nixon amid protests against the Vietnam war.

“I still believe the president will win, but this should be a warning sign that there are large parts of our base that are unhappy,” Khanna said.

“My hope is that the president, I believe, has changed tone and changed course. He’s now using the word ‘ceasefire’. He’s saying that weapons will not be indefinitely transferred to Netanyahu. So my hope is this pressure is going to work on getting a ceasefire and release of the hostages” held by Hamas.