"I have done it before during Indira Gandhi's [Images] time (presided over cabinet meetings)", Pranab Mukherjee [Images] told senior Congress leaders at a meeting of the party's manifesto committee held on Saturday evening.

He was referring to the time when Indira Gandhi was in Cancun in 1981, and there was a hijacking and she had authorized him to preside over cabinet meetings.

As Mukherjee prepares to return to North Block after a gap of 24 years -- he was last there in January 1985 -- and becomes the first minister to sit simultaneously in both North and South Block, it is learnt that Mukherjee would be using the North Block office of the finance minister, which till recently had been used by P Chidambaram [Images].

He is expected to shuffle between the office of the finance minister and the external affairs minister for the duration that he would be handling the finance portfolio. He had once shifted between North Block and the Planning Commission when he was made the deputy chairman of the planning commission along with being the finance minister during Indira Gandhi's regime.

A few Congress leaders had doubts over what exactly was the constitutional position with the prime minister absent from his job and took the opportunity of the manifesto committee meeting to ask Pranab Mukherjee some direct questions. They wanted to know whether he was standing in for the prime minister.

A visibly-relaxed Pranab Mukhejee is learnt to have told them that according to the Indian Constitution there cannot be an officiating prime minister. But under the cabinet of business rules of the government of India, he had been asked to preside over cabinet meetings.

Mukherjee's security apparatus has also not been upgraded since, according to him, 'every agency makes its own assessment', but that is kept to themselves.

While he may not be officially officiating as the prime minister, Pranab Mukherjee did receive the visiting Kazakhstan President Nursultan Nazarbayev during the ceremonial welcome at Rashtrapati Bhawan and also introduced him to ministers and officials who had assembled there. Later, he handled the talks with the visiting dignitary.

Pranab Mukherjee was also briefed by the Cabinet secretary and the principal secretary as part of the customary and daily briefing given to the prime minister of India by the two top bureaucrats in his government.

While this is an internal briefing, the contents of which are top secret, sources disclose that a part of the briefing to Pranab Mukherjee also included the protocol set up for the Republic Day celebrations and how the various functions and activities of the prime minister are being divided up amongst the various senior ministers as well as the President and the Vice President.

While A K Antony as the defence minister would take the salute at the tomb of the unknown soldier, Pranab will accompany him and walk down Rajpath for that ceremony.