Addressing hundreds in the Jantar Mantar area, senior leaders of the Samajwadi Party, the RJD, the INLD, the Janata Dal-United (JD-U) and the Janata Dal-Secular (JD-S) lashed out against the BJP-led government.
"Why has the NDA government failed to fulfil its promises made before the (Lok Sabha) election?" asked JD-U leader and former Bihar chief minister Nitish Kumar.
"Where is the black money it promised to bring back (from abroad)?"
He accused Modi of not acting tough against rightwing Hindu groups charged with religious conversions of Christians and Muslims and said the country should not be divided on religious grounds.
Samajwadi Party chief Mulayam Singh Yadav and Rashtriya Janata Dal leader Lalu Prasad were equally vocal.
"The BJP's conspiracy is to engineer riots so that attention is shifted away from the government's failures," thundered Mulayam Singh Yadav, a former chief minister of Uttar Pradesh.
"They promised jobs to all the youth and Rs.15 lakh to everyone (from the black money they would bring back). They even asked people to open bank accounts. But where is the money?"
Lalu Prasad alleged that Modi was attempting to cause religious divide in the country by tacitly encouraging religious conversions.