Congress Parliamentary Party (CPP) chief on Friday expressed profound grief over Former Prime Minister Manmohan Singh’s demise. In a message, she said Dr Singh was her friend, philosopher, and guide. ‘He left a void in the National life that can never be filled,’ the ex-Congress chief said in her letter. Manmohan Singh passed away on Thursday night at the All India Institute of Medical Sciences (AIIMS) in Delhi. He was 92.