The main reason for this increase is the widening of the scope and ambit of TDS. For example, the TDS rate was early this year hiked from 5 per cent to 10 per cent on brokerages, commissions and fees paid for professional services.

TDS, which is collected on expenditure towards salary, interest, payments to contractors, prizes and rent, now covers around 20 categories.

TDS collections stood at around Rs 37,500 crore (Rs 375 billion) during April-August, about 50 per cent of the gross direct tax collections of Rs 75,244 crore (Rs 752.44 billion). "The share of TDS in the total direct taxes will be significantly higher in 2007-08," said a Central Board of Direct Taxes official.

"A hike in TDS rates, better compliance by firms, along with an effective government machinery are the main reasons for the increase in TDS collections," said Gaurav Taneja, partner, Ernst & Young.

The share of TDS in the total direct tax collestions used to be 60 per cent around a decade back, but higher advance tax payments by corporations due to higher profits led to a decline.

However, the CBDT took steps to reverse the trend by expanding the scope and ambit of TDS. It made electronic filing of TDS mandatory for government offices and companies from 2006-07, leading to better compliance. E-filing of TDS has been extended to all TDS deductors from September 1 this year.

The TDS mechanism has also been strengthened by the creation of 12 new TDS commissionerates and a directorate to monitor the mechanism.

Government-to-government TDS collections have improved and an audit is under way to find reasons why TDS deduction is low in the departments under the Ministry of Defence and the railways.

States which were not crediting TDS collections to the Centre's account in time have also started depositing cash timely after Finance Minister P Chidambaram wrote to state finance ministers.

The income-tax department also launched a special month-long drive in August to educate chief executives and chief financial officers of companies about filing of TDS returns correctly and to persuade non-compliant companies to file their returns.

Only 2.15 million TDS returns were filed by tax deductors in 2006-07. As there are 1.1 million active tax deduction account numbers (TANs) and returns are filed quarterly, the total number of returns during the year should have been 4.4 million had all deductors complied.