The figure has been calculated according to the time required to drive a judge to and from work each day.

But chauffeurs will no longer be available to drive judges for other purposes, such as attending functions or for personal matters.

One High Court judge said: 'All of us are unhappy about it. We were given a warning some months ago that unless we really cut down drastically on the use of the cars, there might have to be a quota allocation.

'Then we didn't hear any more until we received a memo this week from the Chief Justice. We were not really given a chance to express our opinions.' He said the move 'adds insult to injury' because judges' salaries had been frozen for two years.

'It is not that we mind travelling on the MTR or the buses. But I think the idea is to try to keep judges in a situation where they would not have to meet up with the defendant they have just sentenced, or something like that,' the judge said.

A minority of High Court judges drive their own cars. But most use government cars and drivers.

The judge said: 'Technically, we have been able to use the cars to go out to dinner or to go to the market. The usage was not limited to official purposes.' But under the new system, there will be much less scope for judges to use the chauffeur-driven cars in their spare time.

'If a judge takes the car to and from work, he is only left with 2.9 hours a week for other usage,' the High Court judge said.

As well as providing security for judges, the system has enabled them to enjoy the odd drink at social gatherings without having to worry about driving home, the judge said.

'It would be embarrassing for the Judiciary if you were to have judges being prosecuted for exceeding the alcohol limit.' A Judiciary spokeswoman said judges had traditionally used cars and drivers from the government pool on an informal and unlimited basis.

It was considered better to introduce rules governing their use and to apply the quota system to cut costs, the spokeswoman said.