In the event of a midterm Lok Sabha poll, the Congress will not gain seats, says a top secret Intelligence Bureau report prepared for the prime minister's eyes only.

The report also said its allies will lose considerable number of seats, thereby forcing the Congress to enter into a tie-up with the Bahujan Samaj Party to retain power.

The silver lining in the report for the Congress is that the biggest loser will be the its main rival and main opposition party in Parliament Bharatiya Janata Party as its number in the Lok Sabha is assessed to drop from the present 131 to any where between 95 and 100.

The report has been prepared at the instance of the Prime Minister's Office, which directed the IB to get for it the mood of the country through its own survey soon after the monsoon session of Parliament had ended in August.

It says the Congress will get 150 to 155 seats as against 150 seats it has in the Lok Sabha now while the tally of its two main allies -- the Rashtriya Janata Dal of Lalu Prasad and the Dravida Munnetra Kazhagam of M Karunanidhi -- will shrink. DMK's number may drop from the present 16 to anywhere between five and eight while the AIADMK that had drawn blank in the last election may get 12 to 15 seats. The RJD's strength is expected to fall from 24 to 10-12.

Among the losers will be the Samajwadi Party of former Uttar Pradesh chief minister Mulayam Singh Yadav whose number may drop from 38 in the Lok Sabha to 8 to 10 while Uttar Pradesh Chief Minister Mayawati's Bahujan Samaj Party may shoot up its strength in the House from 18 to anywhere between 40 and 45, including some seats from outside UP.

The report assessed the prospects of the Left and other parties as well but the same could not be reported as this correspondent had access to only a few pages of the report.

A top source in IB said the sample survey was conducted in 28 states with the help of a 85-point questionnaire drawn up to evaluate how the electorate would react to various political parties in the event of the polls forced by the left withdrawing support to the UPA government.

The correctness of any such survey or opinion poll depends on the number of persons interviewed and as such one can not say how far dependable the IB survey is as the figures of persons approached with the questionnaire are not available. A retired IB official said the agency conducts such surveys from time to time and the number of persons interviewed varies from 50,000 to 2,00,000 depending upon the subject.