Sources said Mukherjee is likely to reach New York late on Saturday night for his meeting with the Prime Minister on Sunday morning.
They said Mukherjee would explain to the prime minister the disclosure of the Finance Ministry's March 2011 note under the Right To Information Act and also to assess who would be the beneficiary of such a disclosure.
The sources said the note was prepared by officials in a "routine" manner after the PMO had sought a comprehensive paper on the issue.
In order to accommodate his unscheduled meeting with the PM, Mukherjee's departure from Washington has been advanced by a few hours. Now he is expected to leave Washington early Sunday morning instead of afternoon.
He will leave for home in the evening from New York. "He (Mukherjee) is not cutting short his visit. He will fulfil all his engagements in Washington," a Finance Ministry spokesman said.
Mukherjee is in Washington to attend the annual meeting of the International Monetary Fund and the World Bank.
"He will meet the PM in New York on Sunday," the official said.
Sources told mediapersons that Mukherjee, who is in Washington to attend the annual meetings of the International Monetary Fund and World Bank, is heading to New York to meet the prime minister for "obvious" reasons.
The opposition is tageting Chidambaram after a Finance Ministry note, that said 2G spectrum could have been auctioned if the then Finance Minister had insisted, surfaced.
The development takes place a day after the prime minister said he fully backed Chidambaram who "continues to enjoy and inspire my full confidence". Asked whether there was any rift between his two top ministers, Singh said there was no infighting.
The prime minister spoke to Chidambaram on the issue from Frankfurt. Mukherjee had also on Thursday\ spoken to the Home Minister.
Singh is in New York to attend the 66th session of the UN General Assembly and is scheduled to address the world body on Saturday.
The meeting between Singh and Mukherjee is expected to take place after the Prime Minister's address to the General Assembly.
