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 can expect to score enough seats to govern alone.
This will set the scene for frantic horse-trading with a Third Front alliance and an array of regional and other smaller parties once the last of five phases of voting ends on May 13.
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 tomorrow 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.
Participating major parties
Congress
India's centre-left ruling Congress party has the most number of seats in Parliament and pollsters say it may repeat its victory from five years ago. While the mild-mannered economist Manmohan Singh is prime minister, many say the real power in Congress rests with party chief and torchbearer of the Nehru-Gandhi dynasty, Sonia Gandhi. Gandhi and her son, Rahul, are considered two of Congress' biggest assets on the campaign trail.
Bharatiya Janata Party
The mainstream Hindu-nationalist BJP is the largest opposition party in Parliament and heads the National Democratic Alliance. The BJP has strong pro-market credentials but lost the 2004 general election because of what many believe in retrospect was a misjudged "India Shining" campaign message.
Communist Party of India (marxist)
The CPI(M) is India's largest leftist party, which helped Congress to power five years ago and supported it for four years before withdrawing support over a Indo-US nuclear deal last year. The Communists rule in three states, including the populous West Bengal.
Samajwadi Party
The Samajwadi Party came to the government's rescue when it supported the UPA ahead of a trust vote over the nuclear deal last year.The SP has its power base in Uttar Pradesh, India's most populous state. The party, headed by a former wrestler with a long history of criminal charges, relies on the support of the Yadav caste and Muslims, and has wooed some of India's biggest film stars.
Bahujan Samaj Party
It rules in Uttar Pradesh largely with the support of poor Dalits, formerly known as "untouchables". It is headed by the controversial Mayawati, known as the Dalit Queen, who has been tipped as a potential kingmaker and future Prime Minister in case the Third Front, a group of smaller parties, forms a government.