BJP asked the government to come out with facts on Operation Bluestar and sought to know if the action against Sikh militants holed up in Golden Temple was planned on British advice or was any other country also consulted.

"It is about time that the Government of India decided to tell us the truth as to what the real facts were. This would enable the people of India to conclude whether Operation Bluestar was a strategic miscalculation," Leader of Opposition in Rajya Sabha Arun Jaitley said.

Labour MP Tom Watson and Lord Indarjit Singh had stated that recently declassified documents in Britain brought out that Margaret Thatcher regime had sent an Special Air Service officer to India to help advise Gandhi in planning the operation to flush out militants from the Golden Temple.

Following this, British Prime Minister David Cameron on Tuesday ordered an urgent investigation into the issue. Punjab's ruling Akali Dal said the involvement of a foreign nation in issues concerning internal security matters has caused a lot of concern to Sikhs.

Alleging that the 'conspiracy' was hatched in January, 1984, Akali leader Naresh Gujral said, "You invited a foreign country for your internal security matter, India has never done so before."

"The party (Congress) had even gone to the extent of compromising national sovereignty for political gains," SAD secretary Daljit Singh Cheema said in Chandigarh, asking the Congress-led UPA to come clean on the matter after reports "exposed nefarious designs of Congress against Sikhs".

Lt Gen (retd) Kuldeep Singh Brar, who commanded the army division that carried out Operation Blue Star, claimed the operation was planned and executed by Indian military forces and questioned the veracity of such documents that indicated foreign advice ahead of the action.

"I just cannot believe any of this because the operation was planned and executed by military commanders in India. We never saw anyone from the UK coming here and telling us how to plan operation," Brar said.

He said the veracity of these documents must be checked. "There was no involvement (of UK) in it whatsoever. As far as these documents are concerned, I suggest that the authenticity of these must be checked."

In Amritsar, radical outfit Dal Khalsa said, "the Sikh diaspora has been deeply hurt" and wrote to British Premier urging him to clear the air. The chief of SGPC, apex religious body of the Sikhs, Avtar Singh Makkar said the news has left the Sikhs numbed.

Jaitley said instead of exploring alternative methods of evacuating extremists holed up in the Golden Temple, the government went ahead with the operation and hurt Sikh sentiments.

"If British Government was being consulted in February 1984, it only lends credence to the fact that Government of India neither believed in nipping the problem at the initial stage nor in exploring alternative methods of evacuating the extremists from the Golden Temple.

"It wanted to invade the sacred precincts of the Golden Temple no matter even if it hurt the national interest and certainly the interests of the Sikhs," he said.