"Government should not only obtain full details of these accounts, but also make the names of the account-holders public and bring the money back to the country for investment in social projects," party leader Sitaram Yechury told reporters here.
In a statement, the CPI(M) Politburo said the "laxity" of the UPA Government in unearthing black money stashed in Swiss Bank accounts and other tax havens "has been exposed by the recent observations of the Supreme Court".
It said the "unaccounted and ill-gotten wealth, amassed through tax evasion, money laundering and other illegal means, parked in these Swiss Bank accounts should be directly confiscated by the Union Government from the Swiss Banks.
"These monies should be brought back to India and the details of the account holders must be made public," it said, adding that any delay in undertaking these steps would be unacceptable.
Earlier, CPI General Secretary A B Bardhan had said, "What is the secrecy about black money? Why are they not revealing the names? Why are they keeping them (names) under sealed cover? We want to know who they are".
He had said that those who had kept money stashed in Swiss bank accounts had done so to evade taxes. "They are tax evaders. They have committed a crime. The fund should be confiscated."
The Left parties` demand came after the apex court pulled up the government for witholding information on black money stashed in foreign banks, saying it was not just limited to tax evasion but was a "mind boggling crime" amounting to "theft" and "plunder" of national wealth having security ramifications.
Earlier, a Swiss bank staffer had handed over details of 2,000 secret Swiss bank accounts to whistle-blowing site Wikileaks, claiming the list, contained in two compact discs, included names of about 40 politicians, multinational companies and financial institutions from Asia, Europe and the United States.
Maintaining that the website would publish the list in future, Wikileaks founder Julian Assange said he wanted the world to know the truth about money concealed in offshore accounts, how they evaded taxes and the systems in place to keep this secret.