Prime Minister Atal Behari Vajpayee is the head of the Hindu-nationalist Bharatiya Janata Party. He has shown himself adept at maintaining a broad-based range of political allies.
Click on the links below to read about some of the key political figures working with Mr Vajpayee.
India's defence minister, George Fernandes,
is a colourful, outspoken politician whose political career has been as controversial as it has been long.
Mr Fernandes is head of the Janata Dal (United) party. As a veteran socialist, he surprised many when he decided to join forces with the right-wing BJP.
During his stint as defence minister Mr Fernandes is said to have won widespread support among Indian soldiers because of his efforts to improve their working conditions.
But he also had to step down briefly because of an arms bribery scandal but was cleared of any wrongdoing.
Mr Fernandes came to prominence three decades ago as a trade union leader. He led India's largest railway strike in the early 1970s.
One of his most well-known acts was to throw Coca Cola and IBM out of India in 1977, when he was industry minister, in an attempt to protect Indian businesses.
Despite being a life-long campaigner against nuclear weapons, he supported India's nuclear tests in 1998 saying they were necessary to ensure its security.
India's former deputy prime minister is one of the most prominent hardliners in the main party in the governing coalition, the Bharatiya Janata Party (BJP).
He has often been seen as Prime Minister Vajpayee's natural successor if the BJP is returned to power.
Known for his formidable organising skills, Mr Advani is credited with scripting the BJP's rise as a major political force in a short time, from 2 parliamentary seats in 1984 to its present strength.
In 1990, Mr Advani travelled across the country whipping up support for a campaign to build a temple on the site of a mosque in the northern town of Ayodhya.
That led to the violent scenes at Ayodhya in 1992 with the destruction of the 16th century Babri mosque by Hindu hardliners.
Mr Advani has subsequently been cleared of charges that he incited the mob.
LK Advani was born in Karachi in what is now Pakistan. His family migrated to India just before partition in 1947.
He was a member of the Rashtriya Swayamsevak Sangh (RSS), the Hindu nationalist organisation from which the BJP draws its ideological roots.
Mr Advani has a reputation as a efficient and honest if at times ruthless administrator.
He is well known as a Bollywood buff and an enthusiast for the writings of Alvin Toffler about the need to adapt to a changing world.
The chief minister of the southern state of Tamil Nadu, Jayalalitha is a mercurial former film star and head of the regional AIADMK.
She is also one of India's most controversial politicians.
Last year she was acquitted of corruption charges after having been convicted and sentenced in 2000.
In the recent general elections Jayalalitha has once again joined forces with the BJP-and fared very badly.
In 1998 she pulled out of the then BJP-led government forcing fresh polls.
Jayalalitha was brought into politics in 1982 by a former Tamil movie star and state chief minister, MG Ramachandran, with whom she had starred in many films.
Three years after his death in 1988, she took over his party as well as the state.
Her detractors accuse her of having created a personality cult.
Stories about her extravagance are legendary and many of her followers are known to profess their loyalty through bizarre acts such as walking on hot coals or drawing her portrait with their blood.
Her hopes of extending her influence at the federal level have suffered a blow after the drubbing her party received in the general elections.
Chandrababu Naidu remains one of India's most dynamic politicians, despite a resounding election defeat in the state of Andhra Pradesh which saw him lose the post of chief minister.
His regional Telugu Desam party in Andhra Pradesh fared poorly in the general elections as well.
When in office, the reformist Mr Naidu prefered to call himself the "chief executive officer (CEO)" of Andhra Pradesh, describing its people as "stakeholders".
He is one India's most information-technology savvy politicians who believes in what he calls "electronic governance" to cut through the red tape of bureaucracy.
His supporters argue that he has turned Andhra Pradesh's state capital, Hyderabad, into a new information-technology hub and made it an emerging centre for biotechnology.
But his critics say that he did not pay not enough attention to the development of Andhra Pradesh's impoverished rural areas, and the Congress landslide is the price he must pay for this neglect.
His detractors also maintain that he did not do enough to reign in outlawed Maoist rebels who are powerful in some of the poorest parts of the state.
In October he narrowly escaped an assassination attempt by the rebels.
Fifty-three-year-old Mr Naidu has always harboured national political ambitions, but up until now has steadfastly maintained that his first priority was to be a competent chief minister.
Analysts say his election defeat is a blow for the BJP's strategy of developing powerful regional allies outside its Hindi heartland in northern India: such alliances may now more be important than ever if the central coalition is to survive.