The trio, who briefly appeared in court on Friday, allegedly attacked Lt. Gen. Kuldeep Singh Brar on September 30. in central London. Brar sustained a neck wound in the incident.
The accused range in age from 33 to 36, and have been charged with wounding with intent to do grievous bodily harm. One of the men was also charged with common assault on Brar's wife.
The suspects face a further court hearing on January 18.