A scheme to impose automatic £80 fines on motorists without an up-to-date tax disc has been criticised by a motoring organisation.
Persistent offenders can be fined up to £1,000
The AA said it was regrettable that no formal appeal system had been set up by the Driver and Vehicle Licensing Agency in cases of extenuating circumstances.
Under the rules - which come into force from 1 January - fines will be imposed with the use of computerised records.
The AA's Paul Watters said the system was switching from "lax to harsh".
Mr Watters, head of the AA's roads policy, agreed that action was needed to clamp down on motorists who collectively evade some £200m in car tax each year by renewing discs late.
But he said the change was too swift.
"It is a great shame that the DVLA is not going to establish an independent appeals process because there will be many innocent mistakes.
"People will get taken suddenly into hospital and the last thing on their mind will be dealing with paperwork.
"People need to know that if they have genuine mitigation they should have a
legal right to have that heard."
Fine by post
Under the rules, which were unveiled last May but come into effect today,
persistent offenders will be prosecuted and fined a minimum of £1,000.
Offending motorists across the UK will receive their fines in the post.
But Mr Watters argued that the so-called real offenders - those who do not register with the DVLA and are "completely lawless" - would not be snared by the new legislation.
"These people just laugh at the rest of us ... The lawful motorist who makes a simple mistake and is charged £80 will start
to wonder why they see these people getting away with more serious offences."
Shadow transport secretary Damian Green said while he agreed the problem of untaxed cars needed tackling, he thought motorists would see the fines as another form of stealth tax.
The new rules were announced last May by transport minister David Jamieson.
He said they would benefit honest motorists.
"These new measures will protect the majority of honest and responsible
motorists, make the system more secure and make the offenders pay," he said at
The DVLA's deputy manager Jeff Mumford told The Times newspaper that the registration system in Britain has been "too friendly".
He said the DVLA would be sympathetic to drivers who could prove that
they had been in hospital.