Coming in the wake of Patel, political secretary to Congress chief Sonia Gandhi, staving off a determined BJP effort to stall his Rajya Sabha prospects, the opposition had aimed at signalling a fresh offensive.
Congress President Sonia Gandhi on Friday expressed her deep shock at the tragic death of 30 ailing children at a hospital in Uttar Pradesh's Gorakhpur due to alleged shortage of oxygen and said she was pained beyond words by the tragedy.
NCP was, however, conspicuous by its absence, especially in the backdrop of the just concluded Rajya Sabha polls in Gujarat on Tuesday where it was at logger heads with the Congress party over support to senior leader Ahmed Patel.
At the meeting, West Bengal chief minister and Trinamool Congress chief Mamata Banerjee proposed a few joint programmes during the three months before the winter session of Parliament begins in November.
This is the second major opposition party, after Nitish Kumar-led Janata Dal (United), which has distanced itself from a united opposition.
Rahul Gandhi said the BJP government must punish the guilty. He called it a Congress propaganda to project NCP as "BJP's B-team" to damage its credentials ahead of assembly elections in Gujarat.
Apart from the Congress, Left parties, TMC, RJD, JD (U), NCP, JMM, DMK, NC, SP, BSP, RLD, JD-S, Kerala Congress, AIUDF besides some others are slated to participate in the meeting.
According to news agency ANI, senior NCP leader Praful Patel confirmed that the party had boycotted the opposition meeting called by Congress.
In the last two years, Congress vice-president Rahul Gandhi was out for 72 days on six foreign tours, which included places in UK, US, Turkey and Italy, data with top government officials looking at security-related aspects have revealed.
The 18 Opposition parties had earlier made a decision to meet once a month to discuss various crucial issues and maintain better coordination among themselves to "unitedly" take on the government.