The Government has stepped in to block Wandsworth Council from attempting to enforce a 20mph speed limit in its borough.
The council is now in 'ongoing conversations with the Department for Transport (DfT) to try to save the initiative.
As covered exclusively in Highways, experts had raised concerns about the scheme early on suggesting that the way the authority was aiming to use its powers to enforce speed was 'unlawful'.
Now the DfT has also argued it is unlawful and stopped the authority from contacting drivers caught breaking 20mph limits, as well as has asking the DVLA to stop sharing details of drivers caught speeding under the scheme with the council.
A DfT spokesperson told reporters: 'Wandsworth Council is carrying out this experimental speed enforcement trial using powers in a way that is unlawful. We have therefore taken immediate action and asked DVLA to stop sharing registered keeper details with Wandsworth Council for the purpose of enforcing this scheme.;
The abortive trial was launched in November 2022, made the south London borough the first in England to attempt speed enforcement.
The trial was to run on two roads, with an initial warning letter to drivers after they were detected exceeding the 20mph limit and then a civil penalty for each further infringement.
The two roads – Priory Lane and Wimbledon Park Road - were selected as they have high levels of speeding vehicles.
Wandsworth Council said: 'We began this trial as part of our efforts to support the police and Transport for London with their speed enforcement work, and as our contribution to wider London efforts on Vision Zero.
'Since the start of the trial we have seen a 1mph reduction in speeds and the number of vehicles travelling over 25mph dropping from 13% to 6.6% on the trial roads and up until this point have notified motorists who have been found to have breached the speed limit with a warning letter but have not issued any fines.
'The Department for Transport has taken the decision to restrict access to details of registered vehicle keepers, meaning we are now unable to contact drivers who are found to have been speeding. Naturally, we are disappointed with this decision, and are having ongoing conversations with the Department for Transport regarding the future of the trial.
'We remain committed as a council to doing all that we can to reducing the danger posed by speeding vehicles on our roads and hope that the Department for Transport recognises and supports our commitment to ensuring safety on our roads.'
The council originally said the pilot scheme meant drivers caught breaking the rules faced up to £130 fines - cut to £65 if paid in 14 days - but with no points added to their licences.
The council had hoped the scheme could be made permanent and extended to other roads in the borough if successful.
