Politics appears to be a profitable business, as six national parties together registered a total income of Rs.991.2 crore in 2012-13, while they spent Rs.648.7 crore, according to data compiled by a think tank.

The figures come from an analysis of income tax returns of the political parties, even as they continue refusing to furnish details of the donations and funds received, thus keeping their real income in the dark.

Figures from the Association for Democratic Reforms (ADR) and National Election Watch (NEW) showed that the Congress, which was voted out of power in the recent Lok Sabha polls, had the highest income of Rs.425.69 crore.

The Bharatiya Janata Party (BJP), erstwhile opposition party and now in power, was second at Rs.324.16 crore.

The Communist Party of India-Marxist (CPI-M) with 126.09 crore is a distant third, followed by Bahujan Samaj party (BSP) with Rs.87.63 crore, Nationalist Congress Party (NCP) with Rs.26.56 crore, and CPI with Rs.1.07 crore.

While the political parties are liable to disclose details of all donations above Rs.20,000 as per Election Commission directives, the total donations the parties declared was much below their income - Rs.99.14 crore, from 3,777 donors.

In fact, the BSP said it received no donation above Rs.20,000.

The Election Commission makes it binding on political parties to submit annual details of donations - name, address, PAN number of the donor besides the mode and amount of payment - received above Rs.20,000 from all over India.

Of the major sources of income, sale of coupons was listed by most of the major political parties.

Income for the Congress from the sale of coupons/publications amounted to Rs.312.24 crore (73.35 percent of the total income), while the NCP received Rs.3.76 crore from the sale of coupons (14.16 percent of the total income).

Voluntary contributions and donations were listed as the next major source of income by the parties.

Nearly 57 percent of the total Income for CPI-M came through donations while the BJP's donations amounted to 83.76 percent of its total income.

"The Supreme Court gave a judgment Sep 13, 2013 declaring that no part of a candidate's affidavit should be left blank. Similarly, no part of the Form 24A submitted by political parties providing details of donations above Rs.20,000 should be blank," ADR said in a statement along with the report.

The think tank also said full details of all donors should be made available for public scrutiny under the Right to Information Act.

"Some countries where this is done include Bhutan, Nepal, Germany, France, Italy, Brazil, Bulgaria, the US and Japan. In none of these countries is it possible for 75 percent of the source of funds to be unknown, but at present it is so in India," said ADR. The think tank also demanded that national and regional political parties must provide all information on their finances under the RTI Act.