George Galloway has clashed with Sam Coates of Sky News as the veteran left-winger faced criticism from the prime minister after winning the Rochdale by-election.

The Workers Party of Britain leader dismissed “little” Rishi Sunak’s comments, and urged Coates to “suck it up” after repeated questions about the conduct of his supporters during the campaign.

The journalist faced shouts of “bye-bye” and chants of “free Palestine” from Galloway activists as the interview at the new MP’s headquarters wrapped up.

Galloway ran on a pro-Palestine ticket, and pulled off a stunning victory to be elected to parliament for the fourth time, comfortably defeating Azhar Ali, the Labour candidate who was dumped by the party during the campaign.

Ali finished a lowly fourth place behind independent candidate David Tully and Paul Ellison of the Conservatives.

Galloway’s win prompted a reaction from Sunak during an unexpected address from Downing Street on Friday night. The prime minister said: “It’s beyond alarming that last night, the Rochdale by-election returned a candidate that dismisses the horror of what happened on October 7, who glorifies Hezbollah and is endorsed by Nick Griffin, the racist former leader of the BNP.”

When pressed by Sky News, Galloway was dismissive of the PM. “You talk as if this is God,” he said. “You’re talking about little Rishi Sunak, in the fag end of his prime ministership. Don’t talk to me as if he’s come down from the Mount with tablets of stone – the things that he says are somehow meant to awe me. They may awe you, they don’t awe me.”

The interview with Coates, the broadcaster’s deputy political editor, became increasingly edgy.

“Who won the election? Me or Rishi Sunak?,” said Galloway. “I’ve got the democratic mandate here, not Rishi Sunak. He didn’t even come second. He was lucky to come third. So don’t put to me statements made by Rishi Sunak as if I’m supposed to be impressed by them. He don’t impress me much.”

When asked if he respected Sunak, the Rochdale MP fired back: “I despise the prime minister. And guess what? Millions and millions and millions of people in this country despise the prime minister. I do not respect the prime minister at all.”

The mood intensified further as Coates asked about the conduct of Galloway’s supporters during the contest amid allegations of intimidation from rival campaigns.

Again dismissing Sunak’s concerns, Galloway said: “What I care about is that the returning officer, a man of unimpeachable integrity, I’m sure you’ll agree, declared it a free and fair election. And me as the winner, and Rishi Sunak as one of the crushed two big parties of the state.”

He added: “You just have to suck it up. I won the election.”