In August 2006, British police arrested several men for allegedly planning to blow up several passenger jets travelling from Britain. Immediately after the arrests, intense security measures were put in place at airports around the country. It was then that Rabbi Hershi Vogel realised he had a problem. Vogel, the Jewish chaplain at Heathrow, was receiving calls from passengers who were being forced to check their tefilin in as hold baggage. One of these was a South African rabbi who had arrived at the airport en route to New York. Vogel went air-side with his own tefilin so that the rabbi could pray. While he was there, he paid a visit to airport security.

"I went in there and said: 'We have a problem'," says the softly-spoken Vogel. "I opened up the tefilin and showed them what it was all about. I said: Your scanners are very, very good, they can see through the box. If you allow it in the cabin, it would be a blessing'. So they asked me: 'Would it be a problem if they put the tefilin in a see-through bag?' I said: 'Of course not'."

Vogel is sitting in the underground chaplaincy office outside Terminal One. It is a utilitarian, slightly messy space, and the only clue that religious matters are discussed there are the dog-eared Bibles and Qurans lining the shelves.

There are only three airport rabbis in Britain - Vogel, Alan Plancey at Luton and the newly appointed Jonathan Roitenbarg at Manchester. None is full-time, and all work on a voluntary basis, alongside clergy from other faiths.

Vogel started at Heathrow in 1998. International passenger numbers were increasing and the airport management recognised the need to expand its chaplaincy service to include non-Christian religions. Chief Rabbi Lord Sacks asked Vogel to make time alongside his duties at Ealing Synagogue.

Both Vogel and Plancey say that the most important thing for them is to be a visible presence for any passengers - Jewish or not - who require spiritual or practical support. Vogel fingers his bright yellow vest. "They approach me because I wear this," he says. "People see that I'm not working for a particular airline. At the end of the day, I follow my faith and do what's necessary, but if anyone needs my help, I'm there."

One of his biggest challenges is providing help to passengers who are denied entry into the country. "If the law dictates that they are not allowed in the country, I don't mix in," he says. "But, for example, if a person is told on Friday morning that he is not allowed in because he does not have the right visa, I will ask the immigration officer to allow them to stay for the Sabbath. Most of the time I succeed because I'll vouch for the person, and bring them back - it's not a problem."

At Luton, Plancey spends a lot of his time reassuring passengers over his role. "I have to explain that I'm not here because there are dead bodies coming into the airport," he laughs "They seem to think that if they see a rabbi, there's been a tragedy or an accident. It's not! We're here purely as a social service."

Very occasionally, however, the rabbis do have to deal with death. If a person dies in-flight, the standard procedure is to perform an autopsy immediately after landing to determine the cause. If the family of the deceased is particularly religious, this can cause problems, and in the past rabbis have had to step in to appeal to the coroner on compassionate grounds. Happily for Vogel, he has only had to do this once.

Full-body scanners are another bone of contention, especially for strictly Orthodox passengers. But, says Plancey: "If the scan is carried out in a way that preseves modesty, I can't see a problem."

Rabbi Roitenbarg, whose main job is chaplain at Wythenshawe and Hope Hospitals, was security cleared to join the staff at Manchester Airport earlier this month. His appointment comes after he helped out when a Jewish passenger died on a flight from Israel a few months ago. "They couldn't find a rabbi, so I was contacted," he says. He has already been in touch with his colleague at Heathrow. "I spoke to Hershi Vogel - he didn't give me any specific advice, just a general chat."