Israel's Supreme Court has upheld a controversial law barring West Bank Palestinians from living with their spouses and children in Israel itself.
Israel's 1.3 million Arabs are being discriminated against, activists say
By a six-to-five majority, the court rejected petitions brought by civil rights groups, members of the Israeli parliament and Arab Israeli families.
The government says the law, passed at a time of rising violence in 2002, is based on security concerns.
But critics say it is discriminatory and violates rights to a family life.
The case has been described as one of the most important questions the Supreme Court has dealt with in recent years.
One of the groups that challenged the law said thousands of families were affected, that they have been forced to move abroad or live apart.
Orna Kohn, a lawyer for a group defending Israeli Arabs, said Sunday's ruling caused "grave damage to the basic rights of thousands of people".
But the Israeli state says the recent election victory of the militant group Hamas strengthened its case that Palestinians were a security risk and should not be allowed into the country.
There are some 1.3 million Arab citizens in Israel - just under 20% of the population.