There were reports that two MLAs of the NCP in Gujarat might have voted for the BJP and not for Congress candidate Ahmed Patel in the Rajya Sabha elections.
West Bengal Chief minister Mamata Banerjee is slated to attend the meeting.
CPM general secretary Sitaram Yechury "deliberately" left after 40 minutes into the meeting, claiming that his party had problems over an electoral alliance with the Congress, sources said.
USA stocks fall on North Korea worries
Meanwhile, the price of gold , a safe haven for nervous investors, climbed $16 or 1.28 percent to $1,278.70 per ounce at noon. It was the benchmark's worst percentage drop since a 1.8 % decline on that same day in May.
Justifying the no-show, NCP MP Praful Patel said his party was angry at being accused of not voting for Ahmed Patel despite having issued a whip in his favour.
This is the second major opposition party, after Nitish Kumar-led Janata Dal (United), which has distanced itself from a united opposition.
NCP has been urging the Congress to form an alliance for the year-end Gujarat assembly elections, a proposal that was given a cold shoulder by the latter.
He is also organising a conclave in New Delhi on August 17, which will be attended by opposition leaders. Parties that have a strong organisational strength in each of these states could take the lead in organising the programmes and other parties will join them, to make their presence felt on the ground. The meeting was about to talk and discuss the strategy against the Prime Minister Narendra Modi the leading Central Government.
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.