Union Home Minister P Chidambaram today declined to comment on the Finance Ministry note to the Prime Minister''s Office (PMO) that appeared to raise questions on his role in the controversial 2G spectrum allocation.

Chidambaram, who is on a visit to the quake-affected areas in Sikkim, was asked by newsmen here for his response to the note sent by the ministry headed by Pranab Mukherjee but he refused to answer the question.

The March 25, 2011 'secret note' on the allocation and pricing of 2G spectrum broadly suggests that the former Finance Minister could have insisted for an auction of the valuable resource at the time the spectrum was sold on a first come, first served basis when A Raja, now behind bars, was the Telecom Minister.

The note submitted to the Supreme Court yesterday by Janata party leader Subramanian Swamy during a hearing on his petition was written by PGS Rao, Deputy Director in the Finance Ministry, to Vini Mahajan, Joint Secretary in the PMO.

The covering letter to the note also said that Pranab Mukherjee had seen the document.