The Bharatiya Janata Party formally withdrew support from the Karnataka government on Sunday, thus reducing the Janata Dal-Secular government, led by Kumaraswamy, to a minority.
The BJP met Karnataka Governor Rameshwar Thakur at Raj Bhavan on Sunday to inform him about its decision to withdraw support.
The BJP leaders also urged the governor to impose President's rule in the state. Yediyurappa forwarded the resignations of the 18 BJP ministers in the state cabinet.
In the hour-long meeting with Thakur, BJP leaders told the governor that it would be in the best interest of the state to hold elections as early as possible.
With the BJP officially withdrawing support, the JD-S has only 57 seats in the assembly. It needs the support of at least 113 members in the legislative assembly to continue in power.
Meanwhile, Kumaraswamy said that he is ready to face the trust vote on October 18 and added that he is confident of proving his majority. However, he did not explain how he plans to win the trust vote without the support of either the BJP or the Congress.
On Sunday, the BJP organised a mammoth rally in Bangalore to protest the 'betrayal' by the JD-S. The party plans to conduct more such programmes across the state in the next few days.