"I have this day, tendered my resignation from the council of ministers, headed by (Chief Minister) H.D. Kumaraswamy," said Nagesh in a letter to state Governor Vajubhai Vala.
Nagesh, who handed over the letter to Vala at Raj Bhavan in the city centre, also mentioned that he was withdrawing his support to the 13-month-old government.
"I would by this letter, inform your good self that I withdraw my support to the government, headed by Kumaraswamy," said Nagesh.
Nagesh also informed the Governor that he was elected as an Independent from the Mulbagal (SC) Assembly constituency in Kolar district.
Nagesh's resignation comes barely a month after he was inducted into the 34-member Cabinet, along with R. Shankar of the regional party KPJP (Karnataka Pragyavantara Janata Paksha) to ensure their support to his fledgling government facing revolt from a dozen Congress rebel legislators since December.
Shankar, who is Municipalities Minister, also tendered his resignation letter to Congress Legislature Party (CLP) leader Siddaramaiah along with 20 other Congress ministers to pave way for a dozen of its rebels from withdrawing their resignations and making them ministers to save the coalition government from collapsing ahead of the 10-day monsoon session of the state legislature from July 12.
This is the second time Nagesh and Shankar, who represents the Rannebennur Assembly segment, have withdrawn support to the coalition government. They earlier did so on January 15 after being dropped from the ministry on December 22 in a minor cabinet reshuffle-cum-expansion to ensure the government's stability.
The Congress accused the BJP of wrecking its government in Karnataka. "BJP's national leaders are behind this political crisis in the state. They do not want any government or any opposition party to rule in any state. They are destroying democracy," Congress MLA D.K. Suresh told reporters.
The Bharatiya Janata Party (BJP) leaders in New Delhi were quick to retort. "The BJP has nothing to do with the political crisis in Karnataka," Defence Minister Rajnath Singh said in Parliament.
( With inputs from IANS )