Indian lawmakers are voting Monday for the country's next president in a contest that pits two politicians from the lowest Hindu caste rank that were once known as "untouchables."

Prime Minister Narendra Modi's ruling Bharatiya Janata Party is backing 71-year-old Ram Nath Kovind, a lawyer-turned-politician considered the favorite to take over the largely ceremonial post.

He faces 72-year-old Meira Kumar, a former diplomat and the country's first woman speaker of parliament who is backed by the main opposition Indian National Congress party.

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Dalit versus Dalit

The president is chosen by an electoral college composed of the two houses of parliament and state legislatures. In all, 4,120 members of state assemblies and 776 parliamentarians will vote.

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The contest has been described in Indian media as "Dalit versus Dalit," a reference to the low caste origins of the two contenders. 

Dalits, who number around 200 million, continue to face discrimination and live on the socio-economic margins despite decades of affirmative action and laws that nominally provide for equality.

Eye towards 2019

Votes from the Dalits and right-wing Hindu nationalist helped Modi secure a sweeping victory in 2014, as well as pick up several key states including Uttar Pradesh and Bihar.

Analysts say Modi is trying to secure Dalit support ahead of critical 2019 general elections.

India's prime minister has executive power, while the president is head of state with limited powers.

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The new president will replace Pranab Mukherjee from the Congress party after his five year term ends on July 24.

India has previously had one Dalit head of state, KR Narayanan who was president between 1997-2002.

Results from the vote are expected on July 20.

cw/rc (AFP, dpa)