Mark Harper insisted Sadiq Khan’s hated ULEZ expansion is about making money rather than boosting air quality.
The Transport Secretary highlighted how the London Mayor’s own impact assessment stated that widening the zone to cover the whole of the capital would only have a minor to negligible effect on cleaning up the air.
Mr Harper also warned of the prospect of the Labour politician rolling out a pay-per-mile scheme in future.
Meanwhile, a defiant Mr Khan defended his expansion during a bruising round of interviews on the day the expansion comes into force.
Mr Harper told Sky News: “The Mayor’s been saying it’s about air quality, it isn’t. If you look at his own impact assessment that he commissioned it says that it will have a minor to negligible effect on air quality in outer London.
“This is about raising money and putting in place an infrastructure for what on his own website he’s talking about his Project 2030 scheme for road user charging, for a pay-per-mile scheme.
“He’s hiring many posts up to £90,000 a year for a road user charging scheme, to charge people for driving in London.”
It comes as the charging zone, which previously only covered central London, has been expanded to all boroughs from today.
It means more drivers will be forced to pay the £12.50 daily fee for the most polluting vehicles.
But the London Mayor defended the controversial move which has sparked criticism from both the Tories and his own party.
He told BBC Breakfast: “We now have a really effective policy to reduce air pollution.
“It’s shown to be effective in central London and inner London, but I think clean air is a right not a privilege.
“What about outer London? Why shouldn’t they breathe clean air? Why should they carry on dying prematurely in numbers that could be reversed?”
Mr Khan also claimed that the expansion of the ULEZ is not “anti-car”.
And he denied that a pay-per-mile scheme will be introduced while he is in City Hall.
Mr Khan told Times Radio: “I am ruling out a pay-per-mile scheme whilst I am mayor, it’s not on the agenda, it’s not on the table.
“But it’s no secret that the Government, transport officials in London and around the country, have been looking at for some time, in relation to a smarter, streamlined service for a variety of reasons, not least because the Government are worried about fuel revenues drying up over the course of the next few years.
“In fact, Boris Johnson, when he was the mayor of London – remember him? – in his transport strategy there was talk about a pay-per-mile scheme.
“When Rishi Sunak was chancellor he asked his Treasury officials to look into these schemes. There’s no secrecy around this.”
