Senior Congress leader and former Chief Minister Siddaramaiah on Monday resigned as the Congress Legislature Party leader, taking moral responsibility for the party's poor show in the assembly by-polls.
The Congress, which held 12 of the 15 seats where by-elections were held on December five, won only two.
In a letter to Interim Congress President Sonia Gandhi, Siddaramaiah expressed his sincere regrets for not being able to give "satisfactory results" in the byelections.
"I deem it necessary to step down as Leader of the CLP by taking moral responsibility", he wrote.
"As a CLP leader, there is a need to uphold democratic principles. In the interest of the party, I have tendered my resignation as the CLP leader", Siddaramaiah told reporters.
KPCC chief Dinesh Gundu Rao has also resigned, taking moral responsibility for poor show by Congress in the Karnataka Assembly by-polls.