The meeting also chose to constitute a small coordination committee to discuss future strategy against the BJP-led NDA government.
Though the Nitish Kumar-led JDU has been excluded from the list following its realignment with BJP, Congress has signalled a solidarity message by extending invitation to dissenting JDU leader Sharad Yadav, even though he will be in the middle of a Bihar tour on Friday.
West Bengal Chief Minister Mamata Banerjee is slated to be present.
This came amid an atmosphere of distrust after NCP claimed to have supplied the winning vote to Ahmed Patel in the Gujarat Rajya Sabha election, which Sonia Gandhi's close aide refused to readily buy.More news: United States destroyer in South China Sea called 'provocation' by Beijing
More news: Sarahah: All you want to know about internet's new love
More news: Fights Break Out During "Intense" Joint Practice Between Chargers and Rams
The Nationalist Congress Party of Sharad Pawar has also been invited. The move comes amid reports that two MLAs of the NCP in Gujarat may have voted for the BJP and not for the Congress candidate Ahmed Patel in the recently held Rajya Sabha elections.
Sources said that senior leadership of RJD and DMK are also expected to attend the meeting on Friday.
The EC on late Tuesday night declared votes of two Congress MLAs - Bhola Bhai Gohil and Raghav Bhai Patel - invalid. However, Congress leader Ghulam Nabi Azad said the "agenda was to thank the presidential and vice-presidential candidates of the Opposition parties", reported ANI.
"A small coordination committee will be formed of opposition leaders to decide the future programmes", he said.