For the ruling United Democratic Front, it is not only a battle for retaining power in the state but a success would also present an opportunity for the Congress to stage a sort of comeback at the national level after its humiliating loss in the 2014 Lok Sabha elections.
On the other hand, a drubbing in the polls for the Left Democratic Front would spell disaster for it especially at a time when Left is trying hard for a comeback in West Bengal, once a stronghold of the Communists.
The two fronts, ruling the state alternately, will have to factor in the challenge posed by BJP which had put up a better showing in recent civic elections in the state.
BJP, which has failed so far to break the bi-polar politics of UDF and LDF, has this time found a political ally in the Bharath Dharam Jana Sena.
The BDJS is a new party formed by Sree Narayana Dharma Paripalana (SNDP) Yogam, a powerful organisation of backward Ezhava community, led by its General Secretary Vellappally Natesan.
How far the BJP could make inroads into the traditional vote banks of both the Front is being keenly watched by political observers in the state, where the saffron party has so far been unable to win a seat in Assembly or Lok Sabha elections.
UDF, which came to power in 2011 on the slogan of 'development and care', wants to script a new history in the state with a verdict in its favour for 'continuation' of the government.
Over the last decades, Kerala has been witnessing wild swings of votes from one front to another, giving the state alternate governments of UDF and LDF.
Unfazed by the allegations of corruption in solar and bar bribery scams that have hit his government, Chief Minister Oommen Chandy has expressed confidence that the front would return to power on its 'development agenda'.
People were for development and not interested in controversies, he has said.
LDF expects anti-incumbency factor would turn the verdict in its favour, particularity in the wake of solar and bar scams that have rocked the UDF government with some ministers, including, Chandy, being accused of corruption.
Chandy and others have, however, rejected the charges.
There have also been changes in party equations in both the UDF and LDF this time.
In a small setback to UDF, two of its minor parters -- Janathipathiya Samrakshana Samithi (JSS) led by veteran communist leader K R Gouri -- andCommunist Marxist Party (CMP) of late M V Raghavan-- have joined the LDF fold.
Besides, the Kerala Congress (M), third largest partner of UDF, has suffered a split with a group of rebels walking out, accusing the party supremo and veteran leader K M Mani of functioning unilaterally and promoting his son.
The breakaway group is exploring possibilities of cooperation with the LDF in the coming polls.
On the other hand, RSP, a major constituent of LDF, has switched side and is now a partner of the ruling front.
UDF came to power in 2001 with a wafer thin majority of 72 seats in the 140-member assembly. The LDF got 68 seats.
The resignation of a CPI-M legislator R Selvaraj, who represented Neyyatinkara, from the party and switch over to UDF came as a blow to CPI-M in the state. Selvaraja became a Congress MLA after winning the by-elections.
Political parties have welcomed the single-phase polls to all the 140 constituencies.
However, the date of polling, May 16, has come as a surprise to some of the political parties which were expecting it in the middle of next month.
Out of the 140 segments, 11 are reserved for Scheduled Caste candidates while two for Scheduled Tribes.
There will be 21,498 polling stations in the state which is 3.5% more than the last polls.
It has also been decided to set up Voter Verifiable Paper Audit Trial in 12 constituencies.