The Tory mayoral frontrunner has sparked a row over road safety after pledging to lift 20mph speed limits on main roads in central London.
Susan Hall vowed to axe traffic measures introduced by Sadiq Khan, such as the 20mph limit on main “Red Route” thoroughfares such as Finchley Road, which she believes have unfairly penalised Londoners who need to use a car.
But Seb Dance, Mr Khan’s deputy mayor for transport, warned such a move would not speed up journey times and could be dangerous.
He said: “City streets are not motorways, they are shared spaces. They are shared with other road users such as cyclists [and] pedestrians.
“All of the research shows that the average speed in cities is well below 20mph, so you’re not going to get to your destination any [faster]. But the chances of being killed if you are struck by a vehicle at 20mph is significantly less than if you’re struck at 30mph.”
Ms Hall, a London Assembly member, is competing against criminal barrister Moz Hossain KC for the Tory nomination following the withdrawal of Dan Korski.
Transport for London aims to convert almost 90 miles of main roads to 20mph by next May to improve road safety.
Ms Hall said she would retain 20mph limits in residential areas and added: “Around schools, I applaud them.”
In May it was revealed that Archbishop of Canterbury Justin Welby had been caught speeding on the Albert Embankment as he headed towards Lambeth Palace last October. He had been travelling at 25mph in a 20mph area.
The number of people being killed or seriously injured on London roads last year increased by 11 per cent, from 3,580 to 3,974.
TfL says that speed “remains the biggest risk to road users”, with about half of the fatal collisions last year (48 out of 99) reporting speed as a contributory factor.
It said cutting the speed limit to 20mph inside the central London congestion charge zone had helped reduce road collisions by a quarter.