In a statement, the party Polit Bureau said the report sent by US Charge d'Affaires Steven White should be the basis for filing an FIR and initiating an investigation against Satish Sharma and his aide Nachiketa Kapur, who were named in the diplomatic cable.
"The Congress leadership, including the Prime Minister (Manmohan Singh), cannot escape their responsibility in this gross act of political malfeasance and bribery", the statement said.
The party said the US embassy cable that Congress "paid bribes" to MPs to win the confidence vote in July 2008 is an "additional confirmation" of a well-known fact.
"The ''cash for vote'' issue had erupted in the Lok Sabha on the day of the vote itself. But despite the trail of evidence, after an enquiry by a Parliamentary Committee, no action was taken," it said.
According to the leaked cable, Sharma's aide Kapur allegedly showed a US embassy employee "two chests containing cash" and said Rs 50-60 crore is ready for use as "pay-offs" to win the support of some MPs ahead of crucial vote of confidence in UPA government over the Indo-US nuke deal.
Noting that the Congress party machine was working "overtime" behind the scenes in the run-up to the confidence vote on Jul 22, 2008, the cables also claimed the party had allegedly paid Rs 10 crores to each of their "four RLD MPs."
RLD chief Ajit Singh, Sharma and Kapur have denied the allegations.