Prime Minister Benjamin Netanyahu is warning that Israel could be swamped by illegal migrants from Africa.
The mounting number of migrants is high on the national agenda following a series of crimes, including rapes, that have been blamed on the newcomers.
Netanyahu says the influx is "threatening the fabric of Israeli society, its national security and its national identity."
He says if Israel doesn't stop it, then "60,000 infiltrators are liable to become 600,000, and lead to the eradication of Israel as a Jewish and democratic state."
More than 50,000 Africans have poured into Israel since 2005, seeking to escape persecution and poverty.
Some Israelis believe their country, created after the Holocaust, must help the oppressed.