The Prime Minister Dr.Manmohan Singh spoke to Union Home Minister on phone and is understood to have expressed full faith in Mr. Chidambaram' integrity in the 2G spectrum allocation when he was the Finance Minister. The conversation took place during Dr. Singh's stay in Frankfurt where he made an overnight halt on his way to New York. The Prime Minister discussed with Mr. Chidambaram the note sent to PMO by the Finance Ministry in March, 2010 on the 2G spectrum allocation.