Lawmakers across India voted on Monday to elect the country's 14th President amid speculations that ruling NDA candidate Ram Nath Kovind would win with a "comfortable margin" against opposition-backed Meira Kumar.

Kovind -- ex Bihar governor -- has an advantage over Meira Kumar -- a former Lok Sabha speaker -- as the numbers are stacked in favour of the ruling NDA. The BJP and allies have nearly 63 per cent of the vote while the Congress-led opposition has a little over 35 per cent. Independents and other smaller parties, who have not made their choice known, have two per cent.

Polling to choose the successor of incumbent Pranab Mukherjee, who demits office on July 25, started simultaneously in Parliament in the national capital and state assemblies at 10 am. All elected MPs and MLAs are eligible to cast their vote through secret ballot. As voting picked up, many MPs, including women members, were seen queuing up in Parliament House outside the polling booth in Room No 62 for the voting, that closes at 5 pm.

Prime Minister Narendra Modi and BJP chief Amit Shah were among the first to cast their votes in Parliament. Modi, clad in a beige colour sleeveless jacket over a white kurta-pyjama, reached the Parliament premises early to vote on Monday, also the first day of the over three-week monsoon session of Parliament. Congress President Sonia Gandhi and her son Rahul also voted.

In state assemblies, brisk voting was on as MLAs and some MPs also queued up outside their legislative complexes to choose the next President. Polling began on a brisk note in Kerala, Tamil Nadu, Maharashtra, Telangana, Andhra Pradesh, Odisha, Bihar, Uttar Pradesh, as tens of hundreds of legislators voted in the first three hours of polling.

After the completion of the polling, the ballot boxes will be brought to Delhi for counting on July 20. Results will be declared on the same day.