Voting begins in last round of India's marathon election

Indians have began voting in the last round of a six-week-long national election that is a referendum on Hindu nationalist Prime Minister Narendra Modi's decade in power.

The election is considered one of the most consequential in India's history.

If Modi wins, he'll be only the second Indian leader to retain power for a third term after Jawaharlal Nehru, the country's first prime minister.

The seventh round of voting in 57 constituencies across seven states and one union territory will complete polling for all 543 seats in the powerful lower house of parliament.

Nearly 970 million voters — more than 10 percent of the world's population — were eligible to elect a new parliament for five years.

More than 8,300 candidates ran for the office.

Most polls show Modi and his right-wing Bharatiya Janata Party [BJP] leading over the broad opposition alliance that's challenging them, led by the Congress party.

The votes will be counted on Tuesday, with results expected by the end of the day.

Scorching summer temperatures with unusually high heatwaves have compounded voter fatigue in the majority-Hindu country, where unemployment and inflation are the main concerns for voters.

Nearly two dozen election officials died of suspected heatstroke in Bihar and Uttar Pradesh ahead of the vote on Friday, authorities said.

'Sent by god'

Modi's campaign, vying for a third-straight term, began on a platform of economic progress.

He promised to uplift the poor and turn India into a developed nation by 2047.

But it has turned increasingly shrill in recent weeks as he escalated polarising rhetoric in back-to-back incendiary speeches that targeted the country's Muslim minority, who make up 14 percent of India's 1.4 billion people.

Modi, who recently expressed a belief in being divinely ordained rather than biologically born, has also accused opposition of favouring India's minority Muslims, comprising roughly 200 million of the population.

Analysts have long expected Modi to triumph against the opposition alliance, called INDIA [Indian National Developmental Inclusive Alliance], which at no point has named an agreed candidate for prime minister.

His prospects have been further bolstered by several criminal probes into his opponents and a tax investigation this year that froze the bank accounts of Congress, India's largest opposition party.

Western democracies have largely ignored Modi's trampling of rights and democratic freedoms in the hopes of cultivating an ally that can help check the growing assertiveness of China, India's northern neighbour and rival regional power.