During the rally, Yadav launched a scathing attack on the BJP's prime ministerial candidate Narendra Modi, calling him "a killer of humanity".
Addressing a large gathering, Yadav took on the Congress as well, saying both the major parties were detrimental for the country's prosperity.
Modi, the Samajwadi Party veteran said, made fun of BJP president Rajnath Singh's overtures to Muslims.
"After (committing) mass murders, the BJP is now seeking an apology. Can this be accepted?"
Claiming that Modi's charisma would not work in Uttar Pradesh, Yadav denounced the so-called Gujarat model of development.
"There is nothing in Gujarat. Experts have said that the most dirty and polluted rivers are in Gujarat."
Yadav did not spare the Congress party.
"The Congress has no policies for the poor and the minorities. Even the boundaries of the country are not safe in its hands," he added.
Addressing the same rally, Uttar Pradesh Chief Minister Akhilesh Yadav said his government had undertaken several welfare schemes which were now being aped by other state governments.
He promised that by the year-end, Allahabad city would have a new 2,000 MW capacity power plant.
"I'm happy that not one person has left Samajwadi Party to join Congress or BJP," he said.
With agency inputs,