"To leave my children, I would die. I couldn't do it," says Lana Khatib.

Five years ago, Israel's controversial citizenship law marred her first year of marriage and still looms large over everything from supermarket shopping to her fears the family might face the prospect of separation.

Adnan, who is three, and one-year-old Yosra squabble over their toys.

Born and raised in Israel, they are too young to understand that their parents both consider themselves Palestinian, but their father Taiseer is an Israeli citizen while their mother is from the occupied West Bank.

And that means, under the current law, Mrs Khatib cannot apply for citizenship.

Life and death

The law is at the centre of a long legal battle in Israel's Supreme Court, with the latest hearing last week.

For the Israeli government, it's about life and death - the prevention of lethal attacks and the survival of the only majority Jewish state in a post-Holocaust world.

For the law's critics, who include Jewish Israelis as well as Israeli Arabs, it's a struggle to use Israel's self-proclaimed standards of democracy and equal rights to overturn what they see as racist legislation.

Israeli Arabs - people of Arab descent who stayed in Israel after its creation in 1948 - make up about 20% of Israel's population.

They have long faced discrimination, and some Jewish Israelis fear them as a potential "fifth column".

The Citizenship and Entry Law was passed in 2003, during the second Palestinian uprising, as waves of suicide bombings targeted Israeli public places.

Many were launched from the West Bank, some with the help of Israeli Arabs.

Initially, the law - emergency legislation that has since been extended yearly - said that no-one with a West Bank or Gaza ID card would be given permission to move to Israel to be with a spouse there.

It was amended in 2005, allowing women over 25 and men over 35 to apply for temporary permits to live in Israel, but still ruling out citizenship for all but a handful of cases.

In 2007, it was expanded to apply to citizens of Iran, Iraq, Syria and Lebanon.

In contrast, other non-Jews who marry Jewish Israelis can apply for citizenship through a five-year process, subject to individual security checks.

Since the founding of Israel in the wake of the Holocaust, any Jew has been able to move to Israel and claim citizenship.

'Angry and crying'

Mr and Mrs Khatib met in Jenin in 2001. "She is independent, very social, very clever," he said.

When they married three years later, Mrs Khatib was given permission to enter Israel for a single day. The day after, she went back to Jenin, alone, "angry and crying so much".

The following year, they visited each other when they could. Sometimes Mrs Khatib stayed illegally.

"I was always afraid," she says. "It was hell," adds Mr Khatib. "One day you have your wife with you, the next you don't."

Things improved after the amendment. But still Mrs Khatib has no state health insurance.

She is not allowed to work or drive and has to renew her permit every six months.

"It's very insecure. Maybe one day they won't give her the permission and I'll be left alone with two kids," said Mr Khatib.

The law's critics argue that it contradicts Israel's self-declared commitment to equal rights for all its citizens.

Sowsan Zaher, a lawyer for the Israel-Arab rights organisation Adalah - one of several that have petitioned the Supreme Court against the law - says the principle behind it is "very, very dangerous".

"It stereotypes every person just because he belongs to a national and ethnic group and discriminates against him because of that," she says.

In the court, the state's representative defended the law on security grounds.

In the past two years, 27 people who had applied for permission to join their spouses in Israel were directly involved in attempted or actual attacks, she said.

And without the law, the numbers would be much higher, she added.

Another defender of the law, Danny Danon, a member of the Israeli Knesset, or parliament, for the
governing Likud party, says security trumps other concerns.

"The well-being of Israelis comes before any other rights," he says.

But for him there is another issue at stake too - the demographic make-up of the population of Israel.

"I don't think it's a racist law. But we have to make sure Israel stays a Jewish democratic country."

Ilan Tzion, a lawyer for Fence for Life, one of several right-wing organisations also backing the law, put it more strongly.

If the law is overturned, eventually Israel will become "a Muslim state", he says, "the Jewish people will become a minority in their own country", and thus be "exterminated".

"Israel is not like any other country; it was founded on the idea that it will be place for all the Jews in the world as a refuge place," he says.

Case by case

The Khatib family live in the mixed city of Acre in northern Israel. Mr Khatib teaches both Jewish and Arab students at a local college.

"I recognise the state of Israel, but does the state of Israel recognise me?" asks Mr Khatib.

The family could leave Israel, but are strongly opposed to doing so.

"I'm not waking up every day thinking about how to destroy this state, but they are waking up every day thinking about how to kick me out of my place, of the place of my great, great, great, grandfather - before they came here to this land," he says.

Mr Khatib says he understands Israel's security fears. He wants couples to be screened on a case-by-case basis - but Israel says there have been past attackers who would have passed security checks.

The Supreme Court is likely to rule within the next few months.

Campaign groups estimate at least 15,000 couples are affected by the law. Like Mr and Mrs Khatib, they will be watching and waiting.