More than 1,000 people were killed in Operation Bluestar, the raid on the Golden Temple.
Britain's only Sikh lawmaker on Thursday told his fellow members of parliament that Sikhs wanted the full truth about London's involvement in India's 1984 Golden Temple assault.
However, Conservative MP Paul Uppal urged lawmakers to stop trying to politicise the row over what happened 30 years ago on late Conservative Prime Minister Margaret Thatcher's watch.
Current Conservative Prime Minister David Cameron has ordered an investigation by Britain's most senior civil servant to establish the facts, and has pledged to make the results public.
Newly declassified letters show New Delhi had requested British advice over a plan to flush out militants who had occupied the Golden Temple in Amritsar, northwest India - considered Sikhdom's holiest shrine.
With Thatcher's approval, a special forces officer travelled to India and drew up a plan which was approved by India's premier Indira Gandhi.
It is not known how close the February 1984 plan was to the eventual deadly Operation Blue Star raid in June, which triggered a cycle of bloody revenge attacks.
Uppal spoke out after opposition Labour MPs in parliament demanded a quick inquiry and full disclosure of documents.
During exchanges in parliament's lower chamber, the House of Commons, Uppal said Sikhs wanted questions answered.
"As the only Sikh member of parliament in the House of Commons I would just like to advise the chamber that as a Sikh who was 16 years old when the attack on the Golden Temple happened is that 30 years after this event what Sikhs actually want is the end of rumour, suspicion and speculation," he said.
"What they all want is the truth and I would actually ask all MPs to stop politicising this because it is absolutely much more important than that."
The 2011 census found there were 420,200 Sikhs in England, or 0.8 percent of the population.