Dubbing CAG's computation of loss of Rs 1.86 lakh crore in coal block allocation as "flawed" and "misleading", Prime Minister Manmohan Singh on Monday took the battle to the Opposition camp, blaming it for thwarting the Centre's effort to shift to competitive bidding.

Making a statement in both Houses of Parliament amid uproar created by BJP members, Singh refused to be on the back foot, declaring that he takes "full responsibility" for the decisions taken as he contended that CAG's "observations" are "clearly disputable".

With BJP creating disruptions, he read out a few portions of his four-page statement before laying it in Lok Sabha and Rajya Sabha which were repeatedly adjourned because of uproar.

Conscious that the CAG reports are normally discussed in detail in the Public Accounts Committee of Parliament where the ministry concerned responds, Singh said he was departing from this established procedure "because of the nature of the allegations that are being made and because I was holding the charge of Coal Minister for a part of the time covered by the report."

Responding point-by-point to the CAG's observations, the Prime Minister said even if the government auditor's contention that benefits accrued to private companies were accepted, "their computations can be questioned on a number of technical points."

He asserted that aggregating the "purported gains" to private parties "merely on the basis of the average production costs and sale price of CIL (Coal India Limited) could be highly misleading."

As coal blocks were allocated to private companies only for captive purposes for specified end-uses, he said, it would not be appropriate to link the allocated blocks to the price of coal set by CIL.