A leader of United States student protest against Israel’s war in Gaza has been denied legal advice, after US President Donald Trump vowed to deport foreign pro-Palestinian student demonstrators.

Columbia University graduate Mahmoud Khalil, one of the most prominent faces of the protest movement that erupted in response to Israel’s conduct of the war, was arrested and taken to Louisiana over the weekend, sparking protests.

The government has not accused Khalil of breaking any laws, suggesting instead that his permanent residency was being revoked over his involvement in the protests.

His arrest has triggered outrage from critics of the Trump administration as well as free speech advocates, including some on the political right, who say such a move has a chilling effect on freedom of expression.

Khalil had only spoken to lawyers on a monitored phone line from Louisiana and had not yet had a privileged conversation with them, his attorney Ramzi Kaseem told a federal court in New York Wednesday.

Kaseem told the court that he was taken at night as he walked home with his wife and taken 1,000 miles away to Louisiana, noting that Khalil’s wife, a US citizen, is eight months pregnant with their first child.

Judge Jesse Furman then ordered that Khalil receive a daily call protected by client-attorney privilege, meaning the authorities cannot monitor its content. Outside the hearing, hundreds protested in support of Khalil, flying Palestinian flags and holding up banners, while actress Susan Sarandon was at court to back the detained man.