So how could the Israeli authorities get access to the details of British passport-holders?

Here are two ways: one, when people make aliyah, and another, when foreign passport-holders are approached by security services.

Sanjoy Mukherjee made aliyah last year. He said: “Once your aliyah application is approved by the Jewish Agency, you give your passport in and it’s given to the Israeli consulate in London which provides you with an aliyah permit.

"The passport is returned to you and you make aliyah after that. As I recall, my passport was there for around 10 days.”

He noted that many countries requiring an entry visa for tourists can hold a passport, but said: “As a new immigrant, the possibility of one’s passport being used is an issue. That’s not what we signed up for.”

The other route is widely known among new and old immigrants to Israel. One man, who spent a gap year in Israel 40 years ago, said: “We were 18 and on kibbutz. When your madrich (youth leader) says ‘can I borrow your passport?’ you do not ask any questions.

"Mine came back with a Romanian stamp on it. This happened to 30 people. As far as I know Israel was bribing the Romanian regime for olim and people needed a non-Romanian passport to get out of the country.”