Taxi organisations are proposing all passengers should show ID before they are picked up by mini-cabs, following a series of attacks on drivers.

They are planning to trial a system where you must be pre-registered and use special passwords to get a lift home.

There are not many jobs that make you this vulnerable.

Mini cab drivers pick up dozens of strangers a day. Passengers know the have got a pile of cash in the front, but the driver always has his back to them so he can't keep an eye on what they are planning.

'Attacked twice'

A taxi driver was killed in Gravesend at the end of May, another in Sheffield in March. And there have been close calls in Southampton and Lancashire.

The police say the number of attacks is going up, and so is the amount of violence used.

They are now so common, very few are even reported. Mohammed Ijaz Khan is a driver in Derby, and has been attacked twice in the last month.

"I thought maybe I was going to die. He grabbed my neck and the other man pushed a knife into it. I couldn't breathe. I was so scared."

The chairman of one of the biggest taxi associations says he hears stories like that every week. So Steve Wright and the GMB union that represents drivers have come up with an idea to make them safer.

Long before they need a lift home, they want passengers to register their details and be given a secret password or pin number.

Then when they order the taxi, they would have to quote it and show some ID to the driver before they were allowed into the car. Mr Wright calls it "a completely foolproof scheme".

"Unfortunately we're in a violent world and we have to protect our people. And if they know who the passengers are, the chances of an assault are far reduced."

They are in talks with the Mayor of London Ken Livingstone to have the scheme trialled in the capital, with plans to extend to the rest of the country if it is a success.

But first they would have to win around passengers who think it sounds like a lot of hassle.

'Too complicated'

And some police officers too are not convinced. Sergeant Alec Wallace, the community safety officer for Derbyshire, says anything that makes drivers safer is good in principle, but thinks this idea is too complicated to work.

"Just because you know the person it doesn't mean they aren't going to attack you. Then at the end of the day it's extra work for the same fare, they're not getting paid any more. I know the drivers won't do it."

As in Sheffield, he is advocating CCTV cameras in mini cabs as the best way to protect drivers. Mohammed Ijaz Khan is having one of the first fitted in his car.

"I need to do the job - I've got a mortgage and kids. This is the only way to make me feel protected, and keep my wife happy. At the end of the day, it's my safety first, isn't it?"