The anti-defection law defines the grounds under paragraph 2 of the Schedule:
- When an MLA voluntarily gives up his/her membership of a party
- When he/she votes (or abstains from voting) contrary to the directive issued by the party
- Independent members would be disqualified if they joined a political party
- A party could be merged into another if at least two-thirds of its party legislators voted for the merger
In Ravi Naik vs Union of India case, the Supreme Court of India(SCI)ruled that "the words 'voluntarily gives up his membership' are not synonymous with 'resignation' and have a wider connotation. A person may voluntarily give up his membership of a political party even though he has not tendered his resignation from the membership of that party."
In another judgment, the Supreme Court of India(SCI)held if an MLA of a party gives a letter to the Governor extending his or her support to the leader from across the political aisle to form a government, the said member would be considered to have given up membership "voluntarily".
So, if any of the Congress or JD (S) MLAs gives a letter of support to or votes in favour of Yeddyurappa government during the floor test, the member would be liable for defection. But then the Speaker will decide whether the member in question is punishable under the Anti-defection law or not.