Jeremy Corbyn, the former leader of the Labour Party in the United Kingdom who was expelled over antisemitism allegations, has publicly endorsed Zohran Mamdani in the New York City mayoral race. Corbyn showed his support by posting on social media and joining phone-banking efforts organized by the Democratic Socialists of America, encouraging voters to back Mamdani. The alliance between Corbyn and Mamdani, both known for their criticism of Israel and progressive politics, has drawn criticism from political figures, including former New York Governor Andrew Cuomo, who condemned the partnership and called for leadership that rejects extremism and antisemitism.

Mamdani's campaign has also faced scrutiny over alleged illegal foreign contributions, though his team asserts that any financial issues have been resolved. The collaboration between Corbyn and Mamdani has sparked debate within the Democratic Party and among voters, highlighting divisions over progressive politics and allegations of antisemitism just days before the election.