Bengaluru, May 17: BJP legislature party leader B.S. Yeddyurappa took oath as the Karnataka Chief Minister here on Thursday, hours after the Supreme Court declined to stay his swearing-in ceremony.Governor Vajubhai Vala administered the oath of office and secrecy to Yeddyurappa at 9 a.m. at the Raj Bhavan amid tight security.The beleaguered Congress and Janata Dal-Secular (JD-S) leaders, however, protested against the swearing-in of Yeddyurappa and termed the Governor's decision "unconstitutional"."Constitutionally, we (JD-S and Congress) should have been given the chance to form the government as we together have the majority in the assembly. The Governor's decision to invite the BJP to form the government is against the Constitution," state unit Congress chief G. Parameshwara told reporters here.Earlier, a three-judge bench of the apex court rejected a joint writ petition, filed by the Congress and the JD-S on Wednesday night, to halt the swearing-in of Yeddyurappa as the Chief Minister at a special pre-dawn hearing.The top court, however, said the swearing-in of Yeddyurappa was subject to the final outcome of the matter before it and posted the case for further hearing at 10.30 a.m on Friday.The bench, headed by Justice A.K. Sikri, also sought the letter Yeddyurappa wrote to the Governor on Wednesday, informing him about his election as the Bharatiya Janata Party (BJP) legislature party leader in Karnataka.Vala on Wednesday night invited Yeddyurappa to form the government and prove within 15 days that he had majority in the legislative assembly.Although the BJP emerged as the single-largest party winning 104 seats in the May 12 assembly election, it fell short of eight seats from the 112-halfway mark in the lower House, in which the Congress trailed behind with 78 wins and the regional JD-S 37 seats.This is the third time Yeddyurappa took oath as the state Chief Minister, a decade after he became the BJP's first Chief Minister in south India in May 2008 when the party came to power for the first time in the southern state.Soon after taking oath, an upbeat Yeddyurappa said he was confident of winning the majority and being in power for the full five-year term."I am thankful to the people of the state, especially farmers and the poor, who have supported me. As the people are with me, I am confident of winning the majority and be in power for the next five years," Yeddyurappa said at his maiden press conference.Crediting Prime Minister Narendra Modi and BJP's President Amit Shah for his swearing-in as the Chief Minister, Yeddyurappa accused the Congress and JD-S of trying to steal the people's mandate by forming an alliance."The Congress and JD-S have formed an unholy alliance despite people choosing the BJP. We are confident of winning the majority," he added.Among the Congress leaders who protested were former Chief Minister Siddaramaiah, party General Secretary K.C. Venugopal and senior party leader Ghulam Nabi Azad."Yeddyurappa first needs to furnish the list proving his majority in the House," Siddaramaiah told reporters.JD-S supremo and former Prime Minister H.D. Deve Gowda also joined the protest, while his son and JD-S state president H.D. Kumaraswamy attacked the Modi government for "demolishing" democracy."Modi government wants to demolish democracy by targeting the opposition parties. Even when the JD-S and the Congress together have the majority, we weren't invited by the Governor to form the government," lamented Kumaraswamy, a former Chief Minister.In a related development, the Congress and the JD-S have lodged their newly-elected legislators at a resort on the city's outskirts, ostensibly to prevent them being poached by the BJP, which they alleged was indulging in "horse trading" to win over their MLAs."We have a need to safeguard our MLAs from poaching by the BJP, which is why they have been moved to a resort on the city outskirts," Kumaraswamy told reporters later.Congress leader D.K. Shivakumar said the party had the support of all its legislators and its leadership was in touch with all the legislators.