New Delhi, Jan 30 (PTI): In a bid to corner Congress ahead of the Budget session, BJP today launched a fresh attack on it over the Vijay Mallya case, alleging the "corrupt hands" which helped him get bank loans belonged to the then Prime Minister Manmohan Singh and Finance Minister P Chidambaram.

The party quoted from purported letters written by businessman Mallya to Singh in which he sought his intervention and subsequent to which his now-defunct Kingfisher Airline received loans.

BJP spokesperson Sambit Patra asked Congress chief Sonia Gandhi and her deputy Rahul Gandhi to explain at whose behest the defaulting company got loans.

In a press conference, he dragged the Congress leadership into the row, alleging that the then Principal Secretary to Prime Minister Pulok Chatterjee would "snatch files" from Singh to take it to 10 Janpath, Sonia Gandhi's residence.

"The hands which pulled the strings to ensure that Mallya received loans are visible now. It belonged to Chidambaram and Singh.

"Did the hands of 10 Janpath also pull the string? Sonia and Rahul Gandhi should come out in public to say at whose behest the loans were sanctioned to Kingfisher Airline," he said.

"It was after one such letter Mallya had written to Singh on November 14, 2011 that the Prime Minister told the media that 'we have to find ways to get Kingfisher out of trouble'," Patra said.

In another letter, he sought Singh's intervention to get funds from banks released immediately, the BJP leader claimed.

In one of the letters, Mallya said he was very "relieved" and "pleased", apparently referring to developments in the interim, according to Patra.

A top PMO official had spoken to ministries concerned following his letter to Singh and Mallya had mentioned it, he said.

Patra cited another letter the absconding liquor baron allegedly wrote to Chidambaram in March 2013, seeking his intervention to get NOC from the SBI, which headed the consortium of banks which had given unrecovered loans to the airline, and its subsidiaries as his liquor company was in talks with Diageo for a deal.

Asked about Mallya's defence, Patra said they will not listen to a defaulter and he should come back if he wanted to be heard.