Congress has fielded former Chief Minister Narayan Rane, Shiv Sena Trupti Sawant and All India Majlis-e-Ittehadul Muslimeen (MIM) Siraj Khan in the Bandra bypoll in Mumbai.
Trupti is the wife of Sena MLA Bala Sawant whose death necessitated the bypoll.
For Rane, who lost from his home-turf Sindhudurg district in the October Assembly elections, this is almost a do-or-die contest.
NCP has fielded Suman Patil, widow of former deputy chief minister R R Patil, from Tasgaon-Kavathe Mahankal Assembly segment.
The seat fell vacant following Patil's death in February who was elected from the constituency on NCP ticket in October last year.
But there is speculation that some in BJP are covertly helping Swapnil Patil, a youth BJP leader from Tasgaon, who is contesting as an independent.