"It is unlikely that BJP or Congress will form the government at the Centre. It is the third front which will wrest power," he said at an election rally in Kanpur.
Yadav said even if BJP got enough seats in Lok Sabha to form the government, leaders in Narendra Modi's party would prevent him from becoming the Prime Minister.
"The maximum objection to Modi assuming the top post will come from his own party leaders. Because of this, Modi is nervous," he said.
"A BJP leader claims to be in the race for the Prime Minister's post," Mulayam said without divulging the leader's name.
Tearing into the 'Gujarat model' cited by Modi, he said the figures quoted by him were false and maintained that development in Uttar Pradesh was much more than in Gujarat.
Referring to Congress, he claimed that a senior leader of that party told his friend that if SP won the maximum number of seats in Uttar Pradesh, Congress will support it to form the government.
He said since Uttar Pradesh has the highest number of 80 Lok Sabha constituencies, the voters should ensure that SP won maximum seats so that the party could play a key role in the formation of a third front government.
Yadav said if his party was voted to power, income tax exemption limit would be raised to Rs 2.5 lakh and retirement age of government servants raised to 65.
He also promised a slew of measures for the welfare of the farming community.
The SP leader ridiculed Planning Commission's yardstick that any individual who can spend more than Rs 33 a day is above poverty line.
Earlier at Jalaun, he said there was need to improve the living standards of backward Muslims and promised to give them reservation facility like Dalits if his party came to power at the Centre.
Yadav said if SP formed the government at the Centre, poor and most backward Muslims would be given reservation facility like Dalits and recommendations of Sachar Committee would be implemented fully.