Billed as an innovative mechanism to track cash flows in poll campaign, the electoral bonds introduced by the Modi government have brought a windfall for the ruling BJP, official documents suggest. "There will be clean money and a substantial significant amount of transparency as against the present system of unclean money and no transparency," finance minister Arun Jaitely told parliament in January last year while notifying the new instrument. Cut to 2019.

In an RTI reply, the State Bank of India, the sole supplier of electoral bonds, has reported a surge of around 62 per cent in the sale of the instruments over the past one year - from Rs 1,056 crore in 2018 to Rs 1,716 crore in January and March this year. Separately, the Association for Democratic Reforms (ADR), a non-profit election research group, deep dived into tax declarations of various political parties to the Election Commission.

Its report shows funding through electoral bonds is skewed heavily towards national parties, with the BJP walking away with the lion's share. Of the Rs 215 crore generated through the banking instruments in 2017-18, the ruling party secured Rs 210 crore and the opposition Congress Rs 5 crore, the ADR report shows.

The fund flows through electoral bonds have left regional political groups alarmed. "The root of all corruption in India is the nexus between unaccounted money and politics," remarked JD(U) spokesman Pavan Varma.

"Electoral bonds were introduced as a reform ideally to break up this nexus. But the biggest beneficiary of the scheme is the ruling party. If it's a question of a level playing field, what happens to regional parties like us then?" he asked.

Anonymous donors can buy electoral bonds for up to Rs one crore from the SBI and deposit them in the bank accounts of political parties of their choice. The instruments do not identify donors and are exempt from tax. "It's about who is financing," said Trilochan Sastry, founder of the ADR.

"The problem is if only few wealthy people and corporate houses are involved in funding, then the government will work for benefit of those who financed it and not the people. That is a big threat to Indian democracy." The ADR has already challenged the electoral-bond system in the Supreme Court.

In its submissions, the Election Commission has also expressed reservations over political funding through anonymous banking instruments. But the central government insists electoral bonds aim at bringing about greater transparency and defeat the scourge of unaccounted wealth flowing into the country's political arteries. An SC bench is due to hear the matter on April 5.