At least 110 staff members of the PMO attended the farewell function where the PM expressed his gratitude towards them, sources said.
Singh, who became the Prime Minister in 2004, met them in the PMO where he was also greeted by 400 peripheral staff members who gave him a thunderous applause in the corridors of the South Block, they said.
The PMO officials gave the PM a standing ovation. Sources informed that some of the staff who have interacted with the prime minister during the 10 years of United Progressive Alliance (UPA) rule were seen wiping away their tears, the official added.
Top officials, who were present along with Manmohan Singh, were National Security Advisor Shivshankar Menon, Principal Secretary Pulok Chatterjee, Prime Minister's Advisor TKA Nair and his Media Advisor Pankaj Pachauri.
A few pictures of the function have been tweeted from the official Twitter account of the PMO. According to sources, Dr Singh will hold his last Cabinet meeting on Saturday after which he will go and meet President Pranab Mukherjee.
After returning from his meeting with the President, Singh will address the nation, added the sources. On the same day, Singh will host a high tea for the members of his Council of Ministers after which the President will hold a dinner for all of them. The PMO is being refurbished, particularly the upholstery, to welcome a new Prime Minister.