The coalgate issue is expected to generate much heat in Parliament next week, with BJP planning to raise it in a big way during the last week of the extended Monsoon Session.
Party leaders say that it would use every parliamentary device to corner the Congress-led coalition without disrupting the Lok Sabha and the Rajya Sabha.
The issue of missing files relating to coalgate had paralysed proceedings for some time in Parliament earlier during the session, with the Opposition party demanding an immediate response from Prime Minister Manmohan Singh.
Its contention was that the Prime Minister had recently taken full responsibility in the Lok Sabha, so it was incumbent upon him to take Parliament into confidence as to what had happened to the 147 missing files.
It has been claiming that the files included applications for coal blocks have gone missing as some big shots of the Congress were involved.
The issue had also created turmoil in the second phase of the Budget Session of Parliament this year, with BJP insisting on its demand for resignation of Prime Minister over the Rs 1.86 lakh crore coal block allocation scam.
"For us, coal issue is important. It exposes Congress to the hilt. It was on our complaint the CBI is enquiring and government has tried to systematically subvert through every trick in the book.
"Here the Prime Minister is directly accountable. He was the coal minister during the period of scam between 2006 and 2009," BJP spokesperson Prakash Javadekar said.
"We will seek searching clarifications from the Prime Minister on missing coalgate files, because there is involvement of the PMO as well," Ravi Shankar Prasad had said earlier.