Pranab Mukherjee
he Union Finance Minister, Pranab MukherjeePIB

P.A. Sangma and his team has up the ante against UPA's presidential candidate Pranab Mukherjee's nomination for the President post. A three-member delegation of the opposition parties on Saturday approached Election Commission and sought its intervention to initiate a probe into their objections against the former finance minister.

Considering the opposition leaders' request, the Election Commission has directed them to give their demands in writing by Monday.

According to media reports, Janata party chief Subramanian Swamy alleged that Pranab headed two more office of benefits as Chairman of Rabindra Bharti Society and vice president of Birbhum Institute of Engineering and Technology.

The Sangma team also alleged that Pranab's signature on his letter of resignation from the Indian Statistical Institute of Kolkata (ISI) chairman post, was not "genuine."

Initially, former Lok Sabha Sabha Speaker and NDA's nominee for the Preisdent post, PA Sangma moved the Returning Officer, seeking to bar Pranab from contesting for the top post.

However, his attempt failed as the officer responsible for the Presidential poll accepted Pranab's nomination papers after hearing the argument.

Let down by the Returning Officer for polls, Pranab and his supporters were reportedly contemplating on moving the court challenging Pranab's nomination after receiving a copy of the final order about the rejection of their objections, in a bid to take him out of Presidential race.

Earlier, Sangma camp claimed that Pranab held a honorary post in Kolkata-based institution, which was refuted by the ruling Congress-led UPA leaders.

At present, they have cited the Article of Indian constitution, which observes that "superintendence, direction and control of elections to be vested in an Election Commission." The option delegation has sought its directions on president poll regarding their allegations against Pranab.

The 14th Presidential election will be held on July 19.