Speaking to reporters here, he said the erstwhile UPA government had only followed procedures and norms adopted by the previous NDA rule at the Centre in 2G allocation.
Rai's remarks on the role of Manmohan Singh in 2G and coal blocks allocations is absolutely untenable and unacceptable, he said.
He charged Vinod Rai with indulging in 'double speak' as he had not made such comments while holding the post of CAG.
Rai, who is writing a book on his days as head of Comptroller and Auditor General of India, had in an interview criticised Singh.
He said he felt Singh was part of the decisions to allocate 2G telecom spectrum on first-cum-first serve basis and coal blocks without auction.
Narayanasamy also alleged that the Narendra Modi headed government at the Centre was only 'publicity centric' and that issues affecting the people, including inflation, have not been tackled.
