Addressing an election rally in Etawah, Mulayam claimed that Modi would never become the prime minister "as several top BJP leaders were not in his favour".
The SP supremo claimed that several BJP leaders have "contacted" him to say that only he could prevent Modi from becoming the prime minister.
"I want to assure those BJP leaders that we will prevent Modi from being the PM," he said.
He also said BJP was not going to get majority in the Lok Sabha elections and that there was no wave in the favour of the party.
Mulayam claimed that after 2002 Gujarat riots, the then Prime Minister Atal Bihari Vajpayee wanted to remove Modi, but party veteran L K Advani saved him.
Talking to PTI in Mainpuri, Mulayam claimed that third front would form the government at the Centre, with SP as its largest component, and said he would stake claim for the prime minister's post.
The former Uttar Pradesh chief minister replied in the affirmative when asked whether he would stake claim for the prime minister's post.
But, it would be decided by all partners of the front, he said.
The SP leader said that at the initial stage leaders of like minded political parties had held interactions and after long deliberations it was decided that the leader of the third front would be decided after the Lok Sabha elections.
Mulayam said Modi, the BJP's prime ministerial candidate, is no threat to SP and that he is only a "media creation".
Earlier, at an election rally in Mainpuri, he said poor Muslims would get reservation like the backward community and loan of weavers would be waived like that of farmers.
He said that free higher education would be ensured to all irrespective of caste, class or religion.
Attacking Congress, the SP supremo said it was a "dead force" and widespread corruption and high prices of essential commodities would put the party in its proper place.
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