BSP chief Mayawati addresses a press conference at her residence in Lucknow on Wednesday
is furious at arch rival
Mulayam Singh Yadav's comments on her marital status and has suggested that he might need treatment at the "mental asylum in Agra."
Mr Yadav said at an election rally in Faizabad district, "
Main use kunwari kahun, srimati kahun, ya behen kahun (should I call her Miss, Mrs or sister)," referring to Ms Mayawati, who heads the Bahujan Samaj Party or BSP.
The BSP leader retorted, "He (Mulayam) has lost his mental balance due to fear of defeat in Lok Sabha elections... I suggest his family members to admit him to a mental asylum in Agra for treatment."
Ms Mayawati has requested the Election Commission to initiate action against Mr Yadav, who heads the Samajwadi Party, and ban him from campaigning.
Both Mr Yadav and Ms Mayawati are seen as regional powerhouses who have dominated the UP political scene for many years now. Two years ago, the Samajwadi Party ousted the BSP in state elections.
The two parties were almost at par in the last general elections - the SP had won 22 seats, the BSP had won 21.
This year, both are fighting to stay relevant as the BJP, under
Narendra Modi, is expected to make significant inroads in UP, which sends 80 MPs to the Lok Sabha.
(Elections: full coverage)