by Stefan Smith

NEW DELHI - Voting starts this week in India's marathon general elections, which are expected to usher in a period of fragile coalition government for the world's largest democracy.

Opinion polls and analysts say neither the Congress party of incumbent Prime Minister Manmohan Singh nor the main opposition Hindu nationalist Bharatiya Janata Party (BJP) can expect to score enough seats to govern alone.

The elections are being spread out over a month because of the enormous logistics of setting up 800,000 polling booths for the 714 million eligible voters, and rotating six million election staff and security forces.

The first phase takes place on Thursday in the communist-ruled southern state of Kerala, a part of insurgency-hit Kashmir, a swathe of the east where Maoist rebels are increasingly active and in the remote northeast near India's borders with Bangladesh, Myanmar and China.

The most recent national opinion poll, carried out for the news magazine The Week, showed the ruling Congress and its allies on target to retain a similar number of seats as in the current parliament.

It showed the Congress alliance winning 234 seats, the BJP alliance with 186 and the fluid Third Front - which is still in negotiations with charismatic low-caste leader Mayawati Kumari - with 112 seats.

With 543 seats up for grabs, either the left-leaning Congress or the right-wing BJP will have to cobble together an alliance to form a government, and the outcome of the deal-making with often unnatural allies is seen as impossible to predict.

'The Congress-led alliance seems better placed at this point, but there is no one party that can hope for a majority,' said Sanjay Kumar, fellow at the Centre for the Study of Developing Societies.

He said the announcement of the results, due on May 16, "is not going to be the end" of the contest to rule over Asia's third-largest economy and a nation seen as an emerging world power.

'I see May 16 giving us a hung parliament, which will be much more fragmented than before.

'I don't think the government that will take office after May 16 will be a very stable coalition that will last five years. I predict elections again after two or three years.'

Mahesh Rangarajan, professor of history at Delhi University, said Congress was going into the polls with "an advantage, as more parties seem willing to do business with it".

But he said that if the Congress party's own candidates only manage a lacklustre performance, "then finding post-poll partners will be difficult".

'It certainly is an open situation,' he said.

The campaign has seen party leaders criss-cross the nation of 1.1 billion people, some 80 per cent of whom still live on less than two dollars a day.

Poverty, the economy and the situation of debt-ridden farmers have proved fertile battleground issues, as has national security - especially in the wake f the last year's Islamic militant attacks on Mumbai.

Prime Minister Singh, 76, has also been keen to show he is still fit to hold the job, having recently undergone heart bypass surgery.

'I have got a clean bill of good health from my doctors. I just had a meeting with them, so there is no danger to my health,' he told reporters on Monday.

The BJP is also fielding a prime ministerial candidate - 81-year-old Lal Krishna Advani - who in other walks of life would be well into retirement.

Perhaps crucially, the elections will see up to 100 million people cast ballots for the first time, and a recent poll showed a majority of young Indians want a young prime minister.