Finance Minister Pranab Mukherjee on Tuesday declined to comment on latest expose of an inter-ministerial note, which implicates Home Minister P Chidambaram in the telecom scam. While addressing mediapersons in Kolkata, Mukherjee said unless the Prime Minister returns to the country, he would not comment on the controversial issue. A note from the Finance Ministry to the Prime Minister's Office had noted that the 2-G spectrum allocations were done in the knowledge of the then Finance Minister, P. Chidambaram and he could have acted in his capacity to prevent the scam.