Brar, 78, was attacked as he walked with his wife Meena, in Old Quebec Street, central London, on September 30, 2012. Mandeep Singh Sandhu, 34, of Birmingham and Dilbag Singh, 37, Harjit Kaur, 39, of London were convicted of wounding with intent at Southwark Crown Court. Barjinder Singh Sangha, 33, of Wolverhampton, had admitted the charge.
The jury of nine women and two men took just an hour to convict the trio. Lt Gen Brar was involved in a controversial military operation - Operation Blue Star - against Sikh militants in Amritsar in June 1984.
The victim's role in the Indian Army had "made him a target for Sikh extremist groups", the jury heard. Following the verdict, Mari Reid, of the Crown Prosecution Service said: "The group clearly targeted Lieutenant General Brar in revenge for his actions during his military career and today's convictions are another reminder that the UK will not tolerate extremism of any kind."
The couple were on their way from their hotel for a night in the West End when the attack happened. Kaur was described as being key to the ambush. She boarded the same bus as the former soldier and his wife of 28 years in order to follow their movements and phone through reports to the alleged attackers who were waiting.
Sangha "drew a knife as the other men held the victim", the jury heard. Brar was left with a 12 inch cut running across his neck and jaw and another three inch cut to the jaw. The trio, along with Singh Sangha, will be sentenced on September 19, BBC reported.