Bengaluru, Dec 9 (IANS): After a humiliating defeat in the Karnataka by-elections, Siddaramaiah on Monday resigned as the leader of opposition in state Assembly. He has submitted his resignation to Congress chief Sonia Gandhi.

Karnataka Pradesh Congress Committee (KPCC) president Dinesh Gundu Rao also announced his resignation. He, on Monday, tendered his resignation to the party chief Sonia Gandhi, after the party suffered a massive defeat in the by-elections.

Siddaramaiah said, the people's verdict must be respected.

"I express my sincere regret for not being able to give satisfactory results in the bye-elections despite my sincere efforts," Siddaramaiah wrote in his resignation letter and further said that it was his moral responsibility to step down as the Congress Legislature Party Leader.

Siddaramaiah (left) and Dinesh Gundu Rao

Former state Chief Minister was appointed leader of the opposition in the house in October this year despite stiff opposition from the old guard who considers him as an outsider within the party. The former CM had switched side from the JDS.

"Taking moral responsibility, I am resigning as the Karnataka Pradesh Congress Committee president," said Dinesh Gundu Rao at the Congress office.

Rao said that the Congress thought people will not favour the defectors, yet the BJP won.

"Operation Kamala has been ratified by the people," said Rao, describing the way BJP attracted and fielded the disqualified Congress lawmakers.

Rao said he will meet Congress president and submit a detailed report about the party's rout in the bypolls.

In the bypolls for 15 Assembly seats, Congress could manage to win only two seats.

The BJP government led by B. S. Yediyurappa is set to retain power, after winning 12 of the 15 seats that went to bypolls on December 5.