BUSINESSES will not be eligible for volume-related discounts on congestion charges when their vehicles drive into central London, according to fresh details released about the capital's road charging scheme.

Transport for London has announced a series of exemptions to the £5 per day charge, but specifically ruled out the opportunity for organisations to negotiate discounts, even if they have large numbers of essential vehicles entering London every day.

Motorbikes and mopeds, the Royal Mail, buses, the military, emergency services, black cabs, and 'key' vehicles used by London Boroughs (such as refuse trucks) will all escape the charge.

But other employers whose staff travel in and out of the congestion zone will have to pay the full £5 charge for each vehicle, valid for the whole day, irrespective of how many times they come in and out.

Employers will feel pressure to reimburse staff who live outside London but who commute by car into the capital. Permanent residents in the zone will qualify for a 90% reduction.

The news that the Royal Mail has been allowed full exemption from the proposed charging has prompted an angry reaction from commercial courier firms.

Sharon Dance, corporate affairs manager for DHL UK, said: 'It has to be cleared up exactly what the exempt Royal Mail can carry, and how it will be regulated.' She did, however, welcome the exemptions for alternative fuel vehicles, although these are restricted to vehicles that run solely on liquefied petroleum gas, compressed natural gas, or electricity. Bi-fuel vehicles will have to pay to enter the zone. DHL has a fleet of 70 LPG vehicles, three electric TH!NK cars and seven quadricycles in the greater London area.

A 10-week period of consultation started this week, in which the finer details and small print will be discussed. The finalised scheme will be revealed at the end of the year.