A whip is the instruction issued by political parties to vote according to the party line in a legislature. Violation of the party whip could lead to expulsion under the Anti Defection Act.
Sometimes political parties decide on a particular course of action, but may not issue a whip to enforce it, as in the present instance where the Shiromani Akali Dal has taken a decision to vote against the United Progressive Alliance government but has not issued a whip to its members. However reversing the decision on Friday afternoon, the party issued a whip asking it members to vote against the government.
In such a case, the members of Parliament are free to vote as per their choice -- in this case, vote for the government of Dr Manmohan Singh.
But usually, in case of an important vote, a whip is issued
A whip is of three kinds.
In India, under the anti-defection law, a three-line whip can be violated only by more than one-third of a party's strength in the legislature.
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