NEW DELHI: India's GDP growth rate may have dropped in the past few years but that has had little impact on the bottomlines of the country's leading political parties. The coffers of the main parties have been swelling, with the richest amongst them, the ruling Congress, having made a cool Rs 1,662 crore in the last five years till 2011-12 and the BJP in second place with Rs 852 crore.

Not surprisingly, the highest income for these parties came in 2009, when parliamentary elections were held. According to Income Tax returns of these parties, Congress's annual income went up from Rs 220 crore in 2008-09 to Rs 497 crore in 2009-10. In the next two years, the party raked in almost Rs 400 crore per year.

Similarly, BJP's income swelled to Rs 220 crore in 2009-10, up from Rs 124 crore a year earlier. It touched Rs 258 crore in 2010-11.

Last year (2011-12), when economic growth slowed down again - the GDP plummeting to 6.9% from a high of 8.4% in the previous two years - both parties registered a dip in collections. While the Congress made Rs 307 crore, down from Rs 468 crore the previous year, the BJP's collection saw a Rs 90 crore drop, settling at Rs 168 crore.

All major parties continue to source most of their funds from unidentified donors, according to the I-T returns. The donors' lists and returns of the Congress, BJP, NCP and BSP show that these parties have not disclosed the names of entities who account for a major chunk of their funding.

The Association for Democratic Reforms (ADR), which has been campaigning for transparency in funding of political parties and has obtained these I-T returns, has written to the Central Board of Direct Taxes demanding a probe into undisclosed contributions to parties, which constitute up to 90% of their total collections.

"It has been more than a year and the CBDT has not yet responded to our request though they had promised to look into the matter," said Anil Bairwal, coordinator of ADR. He said the sources and flow of such donations needed to be tracked to curb black money infiltrating into the coffers of political parties.

BSP, the party led by former Uttar Pradesh chief minister and Dalit icon Mayawati, stands third in the list of parties with the highest collections. Its income went up from Rs 70 crore in 2008-09 to Rs 182 crore in the election year 2009.

In five years till 2011-12, Mayawati's party received more than Rs 425 crore, mostly through cash donations. It has revealed little about its contributors claiming most donations were below Rs 20,000 and thus exempt under election rules from mandatory disclosure. Some time ago, the party had subverted I-T department's moves to unearth its donors, successfully arguing that all its cash contributions were made by poor supporters out of love and affection for the party leader.

Bairwal said the Congress, which claimed to have collected at least Rs 978 crore through sale of coupons in the five years till 2008-09, did not provided any contributors' list for this collection. It provided details of contributors who together accounted for a paltry Rs 85 crore during this period.

Surprisingly, the Communist Party of India (Marxist) has left behind the Mulayam Singh Yadav-led Samajwadi Party and Sharad Pawar-led Nationalist Congress Party in generating funds. CPM stood fourth in the list, having collected Rs 335 crore in the five years up to 2011-12. SP made only Rs 200 crore during this period and NCP was far behind with Rs 140 crore.