The Election Commission is expected to announce the dates for Karnataka Assembly elections at 11 am on Tuesday.
The term of the 224-member Karnataka Assembly ends on May 28 this year.
The BJP is seeking to wrest control of the southern state from the Congress and has already declared former chief minister B S Yeddyurappa as its chief ministerial candidate.
The ruling Congress is going to polls under the leadership of Chief Minister Siddaramaiah, in its bid to retain its hold over the state. Karnataka is the only big state, besides Punjab, which is now ruled by the Congress.
The JD-S, which is the third force in the state, has announced its pre-poll tie-up with the Bahujan Samaj Party.
It is vital for the Congress to retain Karnataka to set a tone for the 2019 general elections, and also because it is currently in power only in three states — Punjab, Karnataka and Mizoram, besides the Union Territory of Puducherry.
(With agency inputs)