Uttar Pradesh Chief Minister Mulayam Singh Yadav today resigned in the wake of reversals in the assembly elections, but attacked the Election Commission for allegedly hurting the prospects of his party."I have resigned in deference to the mandate of the electorate," Yadav told reporters after submitting his resignation to Governor T V Rajeswar.Governor Rajeswar has accepted the resignation of Yadav and his council of ministers. He, however, asked Yadav to continue as acting Chief Minister along with his council of ministers till an alternative arrangement is made, according to a notification issued by Chief Secretary Shambhu Nath.Yadav said the EC had violated the limits laid down by the Constitution.He claimed the central paramilitary forces deployed by the commission dissuaded people from exercising their franchise, adding that at many places security personnel in plainclothes were present inside the booths."Despite all this, people have voted for us for which we are grateful to them," Yadav said."We will now go to the people. We have always been with the people," he said.He said Congress was "finished for ever" in the state. "Now, the fight is between SP and BSP," he said.Asked about BSP chief Mayawati's reported statemment that she would put him behind bars if she comes to power, he said: "Why don't you go and ask her?"Meanwhile, Bahujan Samaj Party, led by Mayawati, seems all set to emerge as the single largest party in the assembly, and Mayawati is set to return to power for the fourth time.Updated at 1310 hrs: Mayawati's BSP today emerged the single largest party in a fractured verdict in the Uttar Pradesh assembly elections as she prepared to assume the reins of power for the fourth time.The party's strategy of wooing Brahmins and other upper castes in a big way in a rainbow coalition helped add to its traditional vote base of Dalits and Muslims.Victory celebrations began at the Mall Avenue residence of Mayawati, where party workers distributed sweets among themselves and to journalists. Elsewhere in the state, BSP workers set off fireworks.The BJP, which had hoped to do well capping its victories in polls in Punjab, Uttarakhand and Mumbai corporation, also suffered reverses.Chief campaigner Rahul Gandhi's electioneering appeared to have come a cropper with the Congress likely to just about retain its existing number of seats. The party was placed fourth.The Congress indicated it was open to backing Mayawati in forming a government.In the 2002 assembly elections, the BSP had won 99 seats while the Samajwadi Party bagged 143. The BJP was third last time too, winning 88 seats and the Congress had secured 25 seats.The Ajit Singh-led RLD had won 15 seats and the CPI-M one seat. Others accounted for the remaining 32 seats.