Senior Congress leader P Chidambaram said on Thursday state-wise alliances would benefit the party and was the best way to defeat the BJP.
"The kind of alliance that was formed in Karnataka yielded results. Similar alliances should be formed in different states," Mr Chidambaram said, emboldened by the victory of the Congress-Janata Dal (Secular) alliance in the recent by-polls in the southern state.
When asked about the party's alliance in West Bengal, the Congress leader avoided a direct reply, but said it was up to the party high command to decide.
"The by-elections were a big blow to the BJP...The next few weeks will be crucial," he said, indicating to the upcoming elections in five states.
Speaking on the issue of bringing an ordinance for the construction of a Ram temple in Ayodhya, Mr Chidambaram said it would be unconstitutional as the matter was still sub-judice.
On the second anniversary of demonetisation, Mr Chidambaram described it as the "most ingeniously-designed official money-laundering scheme", because, he said, practically every single currency note was officially exchanged at the bank counters.
"Demonetisation did not put an end to fake currency. On the contrary, counterfeiters have successfully counterfeited the new Rs 2,000 and the new Rs 500 notes," the former union finance minister said at a press conference at the Congress office in Kolkata.
Mr Chidambaram also alleged that the Narendra Modi government has completely failed and the BJP had gone back to its Hindutva agenda.
"The government no longer talks about development or 'acchhe din' (better days). There is no talk any more of development or jobs...The only talk we hear is about the Hindutva agenda, temples and statues," Mr Chidambaram said.
He said Prime Minister Narendra Modi, after coming to power in 2014, had appealed the country to put all divisive and controversial issues under a moratorium for 10 years and focus on development. But, Mr Chidambaram alleged, PM Modi himself had resurrected such issues.
"The prime minister himself has resurrected the divisive and controversial issues and all others from the RSS to ministers and minor functionaries of the BJP are talking and writing only about divisive issues," he added.