JOIN USFinance Minister Pranab Mukherjee and Ahmed Patel, Political Secretary to the Congress President, were also present during the deliberations that took place at Parliament House here.
The leaders were at Parliament House to pay floral tributes at the portrait of the country's first Prime Minister Jawaharlal Nehru on his birth anniversary.
The consultations assume significance in the wake of the opposition, including BJP and the Left, threatening to continue to stall Parliament if Raja is not removed from the Union Council of Ministers.
However, Raja has ruled out his resignation, saying he has done everything according to the procedures set by his predecessors. His party chief M Karunanidhi has defended him saying he was not "guilty".
Main opposition BJP and other parties have given enough hints that they would confront the Prime Minister in Parliament to tell what action he intended to take against Raja and why he was being shielded.
The parties also plan to seek an explanation from Singh for the minister's comments that he had kept the PMO in the loop at every stage during the spectrum allocation.
The opposition campaign for the removal of Raja is expected to gain further momentum in the days ahead with the CAG report on the 2G Spectrum allocation pointing to revenue loss of up to Rs 1.76 lakh crore set to be tabled in Parliament.