The Indian government under the then prime minister, Indira Gandhi, had launched a massive offensive codenamed Operation Blue Star to flush out terrorists from the Sikh religious shrine, causing extensive damage, both physical and sentimental.
A high number of Sikhs in Britain, who are said to play key roles in the next election, felt being let down by the UK government's advice on the military campaign in India in 1984.
The Sikhs alleged that the UK government interfered in the Indian affair to save its trade agreement with New Delhi then. They also demanded an independent probe into the issue.
Meanwhile, UK Prime Minister David Cameron told the Sikh community through a video messaging that he hoped that the investigations into the event would assure the Sikhs residing in Britain and elsewhere.