Shehzad Poonawalla, an office-bearer of the Maharashtra Congress, said he would also contest the election if it was conducted in a "genuine" manner.
The Bharatiya Janata Party's bypoll win in four of the six seats it contested has invigorated the party ahead of assembly polls in Gujarat and Himachal Pradesh.
Narendra Modi could be in for a tough fight in Varanasi with the Congress declaring its resolve to put up a formidable candidate against the Bharatiya Janata Party's PM nominee in the Lok Sabha polls and ruling out support to the Aaam Aadmi Party's Arvind Kejriwal.
Prime Minister Narendra Modi, Congress chief Sonia Gandhi and opposition's vice-presidential nominee Gopalkrishna Gandhi extended their best wishes to Naidu.
Back from incarceration, JNUSU president Kanhaiya Kumar on Thursday night delivered a fiery speech peppered with humour at the Jawaharlal Nehru University campus to target the Narendra Modi dispensation and the Sangh Parivar.