Sabotage and overconfidence. Those are the two reasons being attributed by leaders of Chhattisgarh’s ruling Bharatiya Janata Party (BJP) for the shock defeat in the Vaishali Nagar assembly by—election.

The Congress Tuesday stunned the BJP by wresting the Vaishali Nagar seat in Durg district in a close battle with its candidate Bhajan Singh Nirankari defeating the saffron party’s Jageshwar Sahu by 1,228 votes. In November 2008, the BJP had won the seat by nearly 22,000 votes.

A day later, on Wednesday, party leaders took stock and tried to analyse the reasons for the defeat.

“The Congress delivered a complete shocker,” admitted a senior BJP leader.

“I will sum up two main reasons for BJP’s humiliating loss. First, some potential leaders with a hold in Durg district sabotaged the party’s chances. Second, there was the overconfidence of some state leaders, including Chief Minister Raman Singh,” he added.

He said Raman Singh was so confident of success that he went for a visit to South Africa and Mauritius during the campaign and found just a day to canvass for votes.

Reacting to the loss Wednesday, Raman Singh taunted the Congress and said its workers had “got an opportunity after a prolonged period to burst crackers and celebrate victory”.

Referring to the reports of sabotage by some party workers, he said the party would look into the matter.

A jubilant Congress has sought Raman Singh’s resignation on moral grounds, citing his appeal to the people to “vote for the BJP candidate assuming that the chief minister himself was contesting”.