It's up to the Palestinians to formulate their united democratic government however, all the preexisting agreements the PLO and Israel established are then accepted by all the factions as well. Israel has to have guaranteed security and formal acceptance by all Arab League for any creation of Palestinian state. In other words, there won't be a homeland for the Palestinians with a Palestinian state without the presence of Israel, the homeland for the Jewish people as first formulated by the U.N. in 1947.
U.S., allies stage 20 strikes against Islamic State in Iraq (Reuters)
from the article: Hamas: Next Palestinian government will be located in Gaza