Raya is from Haifa and her husband Issam is from a village just 15 minutes' drive from the centre of Jerusalem, as close as Harrow to London. But he cannot live with his wife and children in their north Jerusalem home because his village lies outside the city limits. Under Israel's family unification law he cannot visit his children's school, nor even his wife when she was giving birth in hospital, because the school and the hospital are in Jerusalem and he's a West Banker.

This is the law that the Israeli Supreme Court voted to uphold last week. It applies only to Arab Israelis. Jewish Israelis are free to marry and live with anyone they like (except Palestinians). The Israelis say it's because Palestinian spouses are a security risk. Palestinians say that the motive is ethnic engineering; that the Israelis will do anything to reduce the Arab population.

When Issam married, he applied for a permit to live with his wife, but was refused on the grounds that he had worked for the Palestinian Authority. "It was just excuses when they turned me down because I worked for the PA. What's wrong with that? It's like being a civil servant. They refuse everyone they can." Indeed, of the 3,000 who applied for exemption last year, only 33 were successful.

"Ours is just one story from thousands like us. The Israelis want to achieve just one thing. They want to remove every Arab from Jerusalem. It's easier for me to go on holiday to Germany than it is to visit my children's school in Jerusalem."

Rimaz came from a small village and couldn't get a permit to live with her husband in Jerusalem, so she was forced to live as an 'illegal'. She had a job as a music teacher but could only get to school by climbing over hills and using dirt roads to avoid the checkpoints. She wasn't allowed to drive or take a bus or a taxi. Sometimes she took risks. Once she was driving the children to school when the police stopped her and asked to see her ID. She was arrested. Another time she was in a taxi and the police arrested both her and the taxi-driver and impounded his taxi.

In the end she had to give up her job. Now she has a short-term permit but no one will employ her because they know it could be revoked at any time. "I feel I am losing the best years of my life sitting at home," she says.

"They have changed this law mainly to reduce the number of Palestinian people living in Jerusalem," says her husband Ghassan. "It's been very successful."

The Supreme Court ruling - by 6 votes to 5 - has sparked off a long overdue debate in Israel about discriminatory laws. But family unification is only the tip of the iceberg. Israel uses a whole armoury of seemingly neutral bureaucratic devices - planning permission, building permits, housing densities, residence applications - to reduce the Palestinian population.

The Jerusalem Plan openly sets a target of reducing the Palestinian population from 40 to 20 per cent and a recent surge in the number of house demolitions, evictions, settlement expansion, revocation of residence permits, even the building of parks and open spaces, are all part of a strategy of ethnic engineering. Refusing to let Palestinians from the suburbs (which are in the West Bank) live with their spouses from the City (who have Jerusalem ID cards) is just one of many ways of nudging Arabs out of Jerusalem.

Racism usually takes a more brazen form. It takes a particular cast of bureaucratic mind to use building permits and housing densities as tools of racial discrimination, but the Israelis have done it. Their policies are racist in everything but name and their system is apartheid in everything but name. Indeed a particularly cruel form of apartheid which works by making people's lives miserable, wearing them down, picking them off one by one. It is inaudible and invisible to the outside world until you look at the effects it has on the lives of ordinary Palestinians.

As a country we protest to the Israelis that they breach international law - by annexing Jerusalem, by building settlements, by expropriating Palestinian land, building the wall inside the West Bank, by blockading Gaza. It is high time that we protested about this - their heartless treatment of ordinary families for no other reason than that they are Palestinian.

Martin Linton is parliamentary liaison for the Israeli Committee Against House Demolitions (ICAHD UK)