The trigger for the unusual hearing was a Congress petitioned filed late on Wednesday night asking the court to stop BJP's BS Yeddyurappa from being sworn-in as Chief Minister because the BJP did not the majority. The BJP has 105 lawmakers, including an Independent, in the 222-seat assembly and is seven short of majority.
Abhishek Singhvi, who had filed the petition for the Congress-JDS alliance, argued that the BJP could not claim to get a majority unless it claims it will encourage lawmakers to defect. To this, the Supreme Court bench said this would be covered by anti-defection law.
Mr Venugopal later suggested that this may not be the case. "Defection is one member crosses to other party. Defection law won't apply before elected member is sworn-in as MLA," he said.
The Supreme Court did not eventually put Mr Yeddyurappa's swearing-in on hold, but wasn't entirely convinced by this argument. "You mean before swearing in MLAs can switch sides?" the bench asked, wondering how the BJP intended to cross the majority mark of 112 when the other side, the Congress-JDS combine, had a list of 116 lawmakers on its side.
The JDS and Congress outweigh the BJP. In a situation like this on what basis has Mr Yeddyurappa claimed that he has the support of more than half the lawmakers. The court said they hadn't seen his letter to the governor but "the arithmetic defies in what way he was invited".
Mr Venugopal and Mukul Rohatgi, the government's former top law officer who said he was representing two BJP legislators, had asked the Supreme Court to dismiss the Congress petition, insisting that the court could not stay the governor's decision.
"Heavens won't fall if someone is sworn in. Last time Supreme Court heard in night, the case related to hanging of Yakub Memon", Mukul Rohatgi argued, pointing that the Karnataka case was very different from the one in Goa. In the 2017 case that had also reached the Supreme Court, the senior lawyer said the governor Mridula Sinha had invited Manohar Parrikar because the Congress did not stake claim.
This is the second time that the Supreme Court is holding an overnight hearing. The first was in July 2015 when the top court held a 90-minute hearing in the middle of the night to hear a last-minute petition against the execution of Yakub Memon for his role in the 1993 Mumbai blasts case.
The top court's hearing in the Karnataka case continued for over three hours.
"The governor can't negate democracy... The other side has 104 members and this side, 116.... It is elementary common sense on numbers (which one is greater)," Abhishek Singhvi had countered before a bench comprising Justices AK Sikri, A Bobde and Ashok Bhushan.