The nine-phase Lok Sabha election begins Monday from India's northeast, with polling in five of the 14 seats in Assam and one of the two seats in Tripura.
The six are part of the 543 constituencies where polling will take place from April 7 to May 12. The result will be known May 16.
The Congress is the major force in Assam which it rules while the Communist Party of India-Marxist (CPI-M) is the dominant force in Tripura. But the opposition is aggressive in both states. An estimated 6.4 million people are eligible to vote Monday to pick representatives to the Lok Sabha from Tezpur, Jorhat, Kaliabor, Dibrugarh and Lakhimpur constituencies in Assam.
According to the Election Commission, a total of 51 candidates are in the fray Monday in Assam, which will elect the remaining nine Lok Sabha members on April 12 (three) and 24 (six).
Monday's balloting will be held in 8,588 centres.
The polling is expected to start at 7 a.m. and is likely to end by 4 p.m. Campaigning in all five constituencies ends at 4 p.m. Saturday.
Police and paramilitary forces have stepped up security, more so because April 7 coincides with the Raising Day of the outlawed United Liberation Front of Asom (ULFA).
"There is no specific threat for the election but we cannot take chances," said a senior official of Assam Police.
He said a total of 240 companies of Assam Police and paramilitary forces had already been deployed in the state.
Ten candidates are in the fray in Jorhat, nine in Tezpur, 13 each in Kaliabor and Lakhimpur and six candidates in Dibrugarh.
Among the prominent candidates in Assam are lottery baron Mani Kumar Subba, Chief Minister Tarun Gogoi's son Gourav Gogoi, outgoing Congress MP Bijoy Krishna Handique, veteran Communist Drupad Borgohain, BJP state president Sarbananda Sonowal, union Minister of State for Tribal Affairs Ranee Narah, Mamud Imdadul Haque Choudhury of AIUDF, union minister Pawan Singh Ghatowar, Rameswar Teli of the BJP and Anoop Phukan of the AGP.
The West Tripura Lok Sabha seat goes to the polls Monday. Election in the Tripura East constituency will be held April 12.
According to officials, 1.2 million voters are eligible to vote Monday to pick one Lok Sabha member from among 13 candidates including a woman.
In 2009, the CPI-M's Khagen Das won defeating Congress' Sudip Roy Barman by 248,549 votes.
The Left has won from West Tripura 11 times since the first Lok Sabha election of 1952 and the Congress four times. The Congress For Democracy, a breakaway faction of the Congress, secured the seat in 1977.
This time the main battle in the constituency will be between CPI-M's Sankar Prasad Datta and Congress' Arunoday Saha, a former vice-chancellor of the Tripura University.
BJP state president Sudhindra Chandra Dasgupta, Trinamool Congress state chief Ratan Chakraborty, Tripura Pragatishil Gramin Congress president Subal Bhowmik and Aam Aadmi Party's Salil Saha, a physician, are the other important contenders.
The CPI-M is focussing on the development work it has carried out in Tripura while attacking the Congress for poor governance and corruption in the country.
The opposition is harping on poor governance, unemployment and rising crime against women.
Tripura Chief Electoral Officer Ashutosh Jindal said the Border Security Force (BSF) would seal the India-Bangladesh border during the polls.