LONDON — Former U.K. Labour Party Leader Jeremy Corbyn hosted a phone bank Sunday evening for Zohran Mamdani — and swiftly triggered a backlash from the Democratic New York mayoral contender’s political opponents.

With New Yorkers heading to the polls Tuesday to choose the successor to incumbent Eric Adams, the left-wing British MP announced in a social media post that he was hitting the phones on behalf of the New York City Democratic Socialists of America campaign group to Get Out The Vote for Mamdani.

“Let’s get Zohran over the finish line for a New York that’s affordable for all,” Corbyn — a fellow Arsenal Football Club fan — said as he posed with a North London 4 Zohran shirt.

However, the intervention was criticized by Mamdani’s main opponent, the independent candidate Andrew Cuomo, who attacked Corbyn’s controversial tenure as Labour leader.

After defying the odds to deprive former Conservative prime minister Theresa May of a majority in 2017, Corbyn took Labour to a calamitous defeat in the 2019 election. His stint at the top of Labour drew frequent criticism of the way the party dealt with allegations of anti-semitism in its own ranks, with Britain’s human rights watchdog finding that Labour under his leadership was “responsible for unlawful acts of harassment and discrimination.”

Corbyn was booted from Labour by its current leader Keir Starmer over his response to that report, and now sits as an independent.

“Having Jeremy Corbyn — someone whose party was found to have committed unlawful acts of discrimination against Jewish people under his leadership — phone-banking for Zohran Mamdani says everything you need to know,” Cuomo posted on X.

U.S. Assistant Attorney General Harmeet Dhillon also highlighted Corbyn’s post, appending the message: “Foreign interference in a U.S. election?” There was strong criticism from Republicans when Labour Party activists campaigned for Democratic presidential candidate Kamala Harris in 2024.

Corbyn is not the only European left-winger looking to help with — and learn from — Mamdani’s campaign. French co-Chair of The Left group in the European Parliament Manon Aubry visited New York last week to canvass alongside Mamdani supporters.