London's congestion charge scheme will fail because of technical problems, 43% of engineers surveyed in a poll have said.

The survey also reveals that 66% believe it is reasonable to charge motorists for entering jammed city centres.

However, fewer than half think charging will actually reduce jams.

The results came from responses from 523 engineers questioned in a survey organised by the Professional Engineering magazine.

Fuel hike

Congestion charging, which will see motorists pay a �5 fee to drive into central London, is being introduced on 17 February.

All those surveyed were professional engineers between the ages of 25 and 65 in full time employment.

Most of those polled said they would either pay up or park outside the charging zone in London.

Reactions to another way of reducing car use, by raising the cost of fuel, were also gauged by the survey.

Asked to declare a price for fuel that would drastically change their driving routine, 94 respondents declared between 80 and 99 pence per litre.

Around one third of respondents said �1 per litre would make them change, while nearly every engineer would change their driving routine if petrol reached �2 a litre.