The "instability", he claimed, was caused as Yeddyurappa did not take into confidence his own party legislators and ministers, resulting in his "own MLAs rebelling against him".
Sarcastically congratulating the BJP government, which completes three years in office on Monday, he flayed the government for allegedly not undertaking any developmental works during this period.
"Chief Minister B S Yeddyurappa, who has been harping about development, has not been able to take up any developmental works so far," Kumaraswamy said.
On the JDS carrying out a sustained campaign against the chief minister, he shot back, "should we keep mum when the chief minister is looting the state wealth as per his whims and fancies".
On BJP leader Sushma Swaraj's recent remark that she had "no role in the political making" of Reddy brothers, Kumaraswamy said, "She is trying to escape from the forthcoming problems by doing so. Realisation has dawned on her late".
The JDS legislature party will hold its meeting in Gulbarga on Monday to discuss its action plan in the coming legislature session, he added.