Israeli voting

Are members of the LIkud party the only ones allowed to vote Sunday?

“the Likud Party voted down Prime Minister Ariel Sharon’s plan for a unilateral withdrawal”

How does this work?

Sharon’s plan was controversial within the Likud party, so the party had a non-binding referendum, to get the views of Likud members. It was voting on a single question, and only members of Likud were allowed to vote. It’s not much different than a primary election in the US, where only registered Democrats or Republicans are allowed to vote.

Sharon was hoping, if he got a lot of support for the idea, that he could do it without having to worry about a party revolt. The fact that he didn’t means that he will have to reconsider carrying it out.