Patna Feb 13: Bihar Chief Minister Nitish Kumar on Monday claimed that he knew "from the very beginning" that his alliance with Lalu Prasad's Rashtriya Janata Dal "would not last for more than a year-and-a-half", but he did his best to carry on in the grand alliance, which ultimately disintegrated last year. The grand alliance ministry, headed by Kumar, collapsed in July last year after the chief minister resigned over graft charge against his then deputy, Tejashwi Yadav. Subsequently, Kumar joined hands with the Bharatiya Janata Party to form another coalition government in Bihar. "The very day the mahagathbandhan government was installed, I had said to those close to me that this was not going to last for more than a year-and-a-half. I knew it from the very beginning. I still managed to carry on for 20 months," the Janata Dal-United chief told reporters in Patna on the sidelines of his weekly Lok Samvad (public interaction) programme. He said this while reacting to the allegations of "betrayal of mandate", levelled against him by the RJD and the Congress -- the two other constituents of the erstwhile mahagathbandhan. The grand alliance was formed shortly after the 2014 Lok Sabha polls when Kumar and Prasad decided to bury the hatchet. Both the JD-U and the RJD had suffered a severe drubbing in the Parliamentary election, which saw the BJP putting up its best ever electoral performance, riding on a strong wave in favour of Narendra Modi. However, Kumar's statement drew flak from former JD-U president Sharad Yadav, who had raised a banner of revolt when the Bihar chief minister joined hands with the BJP. "If he (Kumar) knew that the alliance was not going to last, why did he agree for such a tie-up in the first place. It is an illogical thing to say. He is suffering from pangs of guilt for his volte face and trying to justify his actions by such utterances," Yadav told a TV news channel in Delhi. Yadav was disqualified from the Rajya Sabha a couple of months ago, following an application by the JD-U, which had held that the former party president's presence at rallies and meetings organised by the RJD-Congress combine were tantamount to his having "voluntary renounced" the membership of the party. Reacting to Kumar's statement, Tejashwi Yadav tweeted, saying, "This is what I have been saying since the beginning that Tejashwi was just an excuse. Paltu chacha (turncoat uncle) had vicious plans beforehand." "The respected 67-year-old should be ashamed that he made a 28-year-old an excuse for his shenanigans. Uncle, you could have parted ways like a man," Yadav, who is the younger son of Lalu Prasad, said.