Christian organizations in the Holy Land say ties with the Israeli government are the worst ever and have accused the Jewish state of denying visas to some clergy - making them unwelcome in the place of Jesus' birth.

A group of 50 Christian leaders sent a letter to U.S. President George W. Bush asking him to help solve a "crisis" that left some institutions without sufficient staff.

"Relations of the churches and these institutions with the Israeli government may be the worst they have ever been," said the letter, sent to Bush last week and signed by Protestant, Catholic and evangelical leaders.

"Those of us with religious institutions in Israel and the Occupied Territories are no longer able to function normally."

Some groups said they felt Israel was singling out Christians - particularly Arabs - for increasingly harsh treatment.

Others thought they were targeted for appearing too sympathetic to the Palestinians.

Israeli officials said there was no policy of discrimination against Christians despite church complaints that visas for their staff and clergy were regularly denied or delayed.

The letter noted a West Bank barrier Israel is building in what it says is an effort to stop suicide bombers also impinges on pilgrims: "It separates ... Bethlehem from Jerusalem. For Christians worldwide, this structure is cutting off access to holy sites."

Christians constitute some 50,000 of the roughly 3.6 million Palestinians in the West Bank and Gaza.

Christians said some church staff were made to wait months for visas, while others were denied. Arabs were particularly vulnerable because of Israeli security concerns.

"There is a lot of delay, and it is denied to some people like those who come from Arab countries," said Father William Shomali, treasurer for the Latin Patriarchate.

"I don't want to speak of persecution, but it is more like neglect ... It is not in the spirit of Jerusalem," he said.

Shomali said some Christians perceived there was an effort by the Israeli right wing to "Judaise" Jerusalem, also holy to Christians and Muslims.

But Israel blames bureaucracy, not bias, for the hold-ups.

"I think we solved all the problems," an Interior Ministry spokeswoman said. "It takes time when people are coming from Arab countries because we have to send the applications to security. They are the only ones, and sometimes it takes a little time."

The interior minister met with Christian representatives several weeks ago to work out any bureaucratic kinks, she added.

Yet Nancy Dinsmore, who has worked for the Episcopal Diocese of Jerusalem for five years, said she was informed last week that her visa would not be renewed. She said she believed Israel was cracking down on Christians for political reasons, targeting those thought to be sympathetic to the Palestinians.

"I think we are pretty loud and outspoken. A lot of our ministries are service related. In doing this we draw attention to the appalling circumstances in which the community lives."