Naftali Bennett's government failed to gain enough support to extend a ban on citizenship to Palestinian spouses of Israelis. The Citizenship and Entry into Israel Law had been in force since 2003.
Israel's new government faced its first major defeat in Parliament on Tuesday after lawmakers failed to extend the validity of a controversial citizenship law.
The vote, one of the earliest political tests for new Prime Minister Naftali Bennett, was tied 59-59, meaning that the measure lapsed.
For nearly a month, Bennett has been heading a disparate coalition with a wafer-thin majority in the 120-seat parliament.
Tuesday's results highlighted the fragility of the government.
The governing coalition includes eight diverse parties who share just one thing in common: Their contempt for opposition leader Benjamin Netanyahu, whom they ousted as prime minister last month after a record 12 years in power.
What was the law about?
The Citizenship and Entry into Israel Law prevents Palestinians living in the West Bank or Gaza Strip and residents of "enemy countries" from getting citizenship rights after marrying Israeli citizens.
As a result, married couples where one partner was Israeli and the other Palestinian could not live together legally in Israel.
The law had been in force since 2003, during the second Palestinian intifada, or uprising.
It was justified on the grounds of national security, with supporters saying that if Palestinians were granted legal status, they would use it to help carry out attacks against Israel.
Critics, however, derided the law as a discriminatory measure against the Arab minority of the Jewish state.
The law was enacted for one year and extended on an annual basis.
Why did the law not pass?
The law failed to be approved in the Israeli Knesset on Tuesday due to opposition from within the ruling coalition.
Both Jewish left-wingers and Arab conservatives, who are part of the government, strongly opposed the measure.
Even former prime minister Netanyahu, whose Likud party enacted the law and who extended it throughout his tenure, voted against it out of apparent spite for Bennett's government.