New Delhi, Nov 28 (IANS): Veteran Bharatiya Janata Party (BJP) leader L.K. Advani Sunday blamed the government's "utter lack of political will" to check corruption for the around Rs.70 lakh crores ($1.4 trillion) of Indian wealth lying stashed in foreign banks still not being returned.

The senior parliamentarian, in his blog, also favoured India ratifying the UN convention against corruption.

Quoting the Swiss Bankers Association, Advani said Indians have "topped the list of black money depositors at the famous Union Bank of Switzerland (UBS)".

Advani said the BJP's four-member task force of enonomic and security experts in a recent publication estimated that Indian wealth stashed in tax havens overseas "vary from $500 billion (Rs. 25 lakh crores) to $1.4 trillion (Rs.70 lakh crores)".

"The publication adds: The maths of the loot may be disputed, but the fact of the loot cannot be," he said.

He reminded Prime Minister Manmohan Singh of his poll promise "to take action with regard to Indian wealth in foreign banks in the first 100 days of his tenure".

"More than 500 days have elapsed, and yet there has been no movement in this regard. The reason is utter lack of political will," Advani said.

He also wondered at the UN Convention against corruption not being ratified.

"Parliament has remained dysfunctional for two weeks, but the government refuses to accept the unanimous demand of the entire opposition that a JPC probe be ordered into the stinking scandals that have recently been exposed," he said.

The BJP has been stalling parliament's winter session since Nov 10 demanding a joint parliamentary committee to probe the 2G spectrum allocation scam that is reported to have cost the nation a huge financial loss.