A man was arrested after British opposition Labour leader Jeremy Corbyn was hit by an egg while on a visit in his north London constituency on Sunday.
A Labour Party source said Corbyn was visiting a mosque and Muslim welfare centre on Sunday and was unharmed.
"A 41-year-old man was quickly detained by officers on scene and arrested on suspicion of assault," the Metropolitan Police said. "He is currently in custody at a north London police station."
British media reported the arrested man was a pro-Brexit campaigner.
On Thursday, Mr Corbyn said Labour would back a new referendum on Brexit after parliament defeated its alternative plan for leaving the EU.