Thousands of parties and candidates will run for office between now and May 19 in 543 constituencies across the nation of 1.3 billion people, with results not due until May 23
India's gargantuan election, the biggest in history, kicked off on Thursday with Prime Minister Narendra Modi seeking a second term from the South Asian behemoth's 900 million voters.
Opinion polls put Modi, 68, as the favourite but he faces a tough challenge from not one but two scions of India's storied Nehru-Gandhi dynasty attempting to capitalise on his poor record on jobs and rural poverty.
Because of the vastness of India, the election will be held in seven phases, from the tea plantations of Darjeeling to the slums of Mumbai to the tropical Andaman Islands, and everywhere in between.
Security forces were on high alert due to the perennial danger of violence at election time, with five people including a local lawmaker killed in an ambush by suspected Maoist rebels this week.
Thousands of parties and candidates will run for office between now and May 19 in 543 constituencies across the nation of 1.3 billion people, with results not due until May 23.
Some of the 1.1 million electronic voting machines will be transported through jungles and carried up mountains, including to a hamlet near the Chinese border with just one voter.
Phase one on Thursday saw some 142 million people cast ballots.
Polling stations in the northeast were among the first to open at 7:00 am (0130 GMT) with others elsewhere set to follow at 8:00 am.
"I call upon all those whose constituencies are voting in the first phase today to turn out in record numbers and exercise their franchise," Modi said in a tweet just after voting began.
"I specially urge young and first-time voters to vote in large numbers," he said.
Modi and his right-wing Bharatiya Janata Party (BJP) swept to power in 2014 with their famous promise of "achhe din" ("good days"), becoming the first party to win an absolute majority in 30 years.
Critics say the BJP has since sought to impose a Hindu agenda on India, emboldening attacks on Muslims and low-caste Dalits trading in beef - cows being holy for Hindus - and re-writing school textbooks.
Modi has simplified the tax code and made doing business easier but some of his promises have fallen short, particularly in rural areas where thousands of indebted farmers have killed themselves in recent years.
Growth in Asia's third-biggest economy has been too slow to provide jobs for the roughly one million Indians entering the labour market each month, and unemployment is reportedly at its highest since the 1970s.
Rahul Gandhi, 48, hoping to become the latest prime minister from his dynasty - and aided by sister Priyanka - has accused Modi of causing a "national disaster".
Gandhi's Congress party has profited from voter dissatisfaction, winning in December three key state elections, chipping into Modi's core support base in the Hindi-speaking heartland of northern India.
Gandhi, the great-grandson, grandson and son of three past premiers, has grown in stature since being derided in leaked US diplomatic cables in 2007 as an "empty suit".
Election adverts show him hugging an emaciated peasant woman, while Congress's leftist manifesto pledges to end abject poverty by 2030 and give cash transfers to 50 million families.
But Modi and the BJP's formidable campaign juggernaut - backed by a savvy social media army - will be no pushover, promising a $1.4-trillion infrastructure blitz.
Playing to its Hindu base, the BJP has also committed to building a grand temple in place of a Muslim mosque demolished by Hindu mobs in the northern city of Ayodhya in 1992.
But most importantly, India's latest military altercation with arch-rival Pakistan in February has allowed Modi to portray himself as the "chowkidar" ("watchman") protecting mother India.
"Nationalism is our inspiration and inclusion and good governance is our mantra," Modi, whose stern bearded face stares out from ubiquitous posters, said at the launch of his manifesto.
But opinion polls are notoriously unreliable in India and much will depend on the BJP's performance in several key states, in particular Uttar Pradesh and West Bengal.
"It's difficult to predict," said Parsa Venkateshwar Rao, a veteran journalist and political commentator.
"It reminds me of 2004 when (premier Atal Bihari) Vajpayee and the BJP lost when everyone expected them to win," he told AFP.