The state government knew the decision can be challenged and accordingly it should have filed a caveat, Fadnavis told reporters here.
He reiterated his party's opposition to the 5 per cent Muslim reservation, saying, religion based reservation was unconstitutional and it was exploring means to oppose the move.
Fadnavis also flayed the government for stopping the probe into the Rs 138 crore Agriculture Product Marketing Committee (APMC) fraud, in which Nationalist Congress Party (NCP) minister Shashikant Shinde is allegedly involved.
Meanwhile, Agriculture and Marketing Minister Radhakrishna Vikhe Patil, has recently put a stay on the order of Director (marketing) Agriculture department, Bhaskar Patil, to probe the irregularities by the Vashi APMC board.
Fadnavis demanded Shinde's resignation and said the opposition will raise the issue at the right time.
Earlier in the day, the state BJP chief launched the "Dream Maharashtra" campaign initiated by Y4d (Youth for democracy, youth for development), a forum of young professionals from all walks of life from different parts of the state.