A group of ultra-Orthodox Israeli parents of European origin are facing jail for refusing to obey a court ruling ordering them to let their daughters study with Jewish girls of Middle Eastern descent.

Israel's supreme court has given the parents until today to send their kids back to school - or face jail in a move likened by one Israeli newspaper to America's use of troops to enforce desegregation in the 1950s.

The case involves around 40 couples who belong to the strictly-observant Slonim Hassidic sect of Ashkenazi Jewry, whose roots are in eastern and central Europe.

The parents, who live in the West Bank settlement of Immanuel, are refusing to let their daughters study at the Beit Yaakov girls' school alongside girls of Sephardi origin, those who originate from North Africa or Asia. When Israel's supreme court ruled in August 2009 that Sephardi girls must be allowed to attend the same classes as the Ashkenazis, parents of 74 children took them out and set up ad hoc lessons elsewhere in the settlement.

On Tuesday, the court gave the Ashkenazi parents until yesterday to submit written pledges to obey their ruling or spend at least two weeks in jail for contempt of court.

But the parents refused to comply and were packing their bags ahead of starting their jail term today.

Aliza Lagon, mother of two girls, told army radio she and her husband would both go to jail, leaving their daughters and two younger children in the care of a friend.

"I shall go with my head held high," she said. "For the education of my children, for the sanctification of the name (of God), for everything in which I believe, for my Judaism."

"I shall go of my own accord," Yitzhak Feinberg, a father of two pupils at the school, told the radio. "I think (supporters) will escort us there and there will be a demonstration."

Ultra-Orthodox supporters of the defiant families vowed to hold a mass demonstration in Jerusalem today and to accompany the errant parents to a local police station from where they would be taken to jail.