With Home Minister and former Finance Minister P Chidambaram coming under the 2G scanner, the main opposition BJP is targetting the minister on the issue. The party has sought a thorough inquiry into Chidambaram's role in the multi-billion dollar scam. Chidambaram's name cropped up in a letter sent by incumbent Finance Minister Pranab Mukherjee to Prime Minister Manmohan Singh in March 2011 saying, Chidambaram as then Finance Minister could have prevented the scam. But the Congress is sticking by Chidambaram, claiming there's no truth to the allegations.