By Soutik Biswas BBC News Online correspondent in Delhi

BJP hopes of a decisive majority are slipping - if you believe exit polls

With counting due on Thursday, the exit poll forecasts have been dominating political talk.

Politicians are sweating it out in television studios, parrying tricky questions about the apparently changing fortunes of their parties.

Election pundits, most of them senior journalists, have been changing tack through the three-week voting process - because the exit polls have shown up different results.

The five exit polls conducted by different channels in India's fiercely competitive television news scrum are practically setting the agenda for the political discourse.

When the main opposition Congress party was trailing in exit polls after the first round of polling on 20 April, party leaders went on the offensive, rubbishing the findings.

But exit polls after the second main phase showed Congress and its allies narrowing the gap.

Then it was time for leaders of the ruling Bharatiya Janata Party (BJP) to pooh pooh the polls - and the Congress party was delighted.

Pressure

The newspapers have also been feeding on the exit poll frenzy by showcasing their results prominently as a way of holding reader interest in the staggered election.

Newspaper headlines scream the latest exit poll findings

They highlight the BJP-led coalition's apparent sharp fall since voting began, compared with pre-election predictions.

One much talked-about poll in an Indian news magazine gave the ruling coalition more than 300 of parliament's 543 elected seats - although the poll's validity must be in question as it was conducted some six months before elections started.

Psephologists will tell you that voters' views usually change several times in the run-up to voting - for example when parties name alliance partners or candidates, or the date of the election is announced.

But the media-hyped polls are putting a lot more pressure on the politicians.

Even Prime Minister Atal Behari Vajpayee conceded recently that exit polls were an "indicator", although sometimes they do go topsy-turvy.

Poll problems

Some analysts think television exit polls, which have a mixed history in India, could be fundamentally flawed.

There is often a disconnect between election polls and what is happening on the ground Media analyst Dr N Bhaskar Rao

Senior Delhi-based psephologist and media analyst Dr N Bhaskar Rao says the "huge numbers of voters" being polled is a major problem.

He believes the exit pollsters are trying to outdo competitors and impress their clients, viewers and readers.

One polling agency has been running samples of a 100,000 respondents across the four main rounds of voting - possibly one of the largest-ever sample sizes in the world.

"But more is not merrier in exit polls. The bias element in exit polls is higher than in opinion polls before elections. So the more the number of people polled, the more is the error," Dr Rao told BBC News Online.

Dr Rao says there are other problems with Indian exit polls as well.

He says women are not proportionately polled, and sampling is "almost always not done properly" in violent areas.

'Million mutinies'

Clearly, away from the chattering classes and the brouhaha over opinion and exit polls, there is an India which keeps on springing surprises and voting very differently.

Voting 20, 26 April and 5, 10 May Counting of votes on 13 May 675 million eligible to vote 543 MPs elected for five years 1 million voting machines Log up to five votes a minute Voting timetable in detail Gearing up for electronic vote

In this India - where novelist VS Naipaul famously commented that a "million mutinies" are under way - local word-of-mouth perceptions about a political party or a candidate almost always count for more than any media spin.

"There is often a disconnect between election polls and what is happening on the ground," says Dr Rao.

Independent studies in India have always found that turnout during elections is usually higher in places where the media has lowest reach, and vice-versa.

But do opinion and exit polls affect voter behaviour?

A study by the Delhi-based Centre for the Study of Developing Societies (CSDS) found that a third of voters it sampled admitted to knowing about opinion polls during the 1996 and 1999 general elections.

But only a few - just over 3% - said they had been influenced by the polls.

Could it be that exit and opinion polls remain largely a luxury of the chattering classes and a news media environment which needs prime-time excitement and spectacle?

The final exit polls forecast anything between 230 and 270 seats for the BJP and its 22-party alliance, and 170-191 seats for Congress and its allies.