Teddy bears or other cuddly toys also are not allowed.

Airline officials, who have sparked outrage, the paper says, explain the Islamic kingdom's strict laws – enforced by religious police – prohibit public practice of Christianity and figures of animals.

BMI spokesman Phil Shepherd said: "In providing air services people want, demand and use, we have an obligation to respect the customs of the destination country."

An airline employee who asked not to be named told the Mirror: "It's outrageous that we must respect their beliefs but they're not prepared to respect ours."

The employee said his grandmother gave him a crucifix shortly before she died that he wears at all times.

"It's got massive sentimental value and I don't see why I have to remove it," he said.

The airline's staff handbook says: "Prior to disembarking the aircraft all female crew will be required to put on their company issued abaya. It will be issued with the headscarf which must be worn."

The employees' union wants staff members to be able to opt out of the flights, but the airline says the only option is to transfer from overseas staff to domestic flights, which could mean a loss of about $30,000 a year in wages.

About 40 staff members have filed complaints since the route began in September.

Some of the male members who are homosexual have called in sick, because they are afraid of traveling to Saudi Arabia, where homosexual activity is punishable by flogging, jail or death.