According to stolen papers, Sadiq Khan contemplated taxing drivers in London up to £2 per mile.

The Labour mayor's push to reach aggressive net zero goals was supposed to include the launch of the flagship pay-per-mile road pricing program in September 2026.

The ideas would have seen the cost of car travels from outer London into the core of the metropolis practically trebling.

It follows The Telegraph's earlier revelation that Mr. Khan had used £150 million of public funds on "secret technology" to implement pay-per-mile road pricing.

Because net zero policies that force the transition to electric vehicles in the upcoming years would cost the Treasury £30 billion in tax income, such road pricing plans have been dubbed "inevitable."

Plans leaked on Tuesday showed how the London mayor plotted to charge motorists up to £2 per mile to drive inside the current congestion charge zone, on top of a £5 daily tax.

Mr Khan has since made clear he has “ruled out” the pay-per-mile policy. However, internal modelling by Transport for London (TfL) – seen by the London Centric blog – shows the proposals would have added tens of pounds to road journeys in the capital.

Under the Labour mayor’s plans, the cost of driving from Upminster to Oxford Circus and back again would have almost trebled, rising from £15 – for the congestion charge – to around £40.

Similarly, at present somebody driving a Ulez-compliant car on a 30-mile return trip across “inner London” from Highgate to Fulham would have incurred no cost other than petrol.

Under the TfL modelling, the journey would have cost an extra £18 in pay-per-mile charges, according to the London Centric blog.

Codenamed Project Gladys inside TfL, the scheme was formally known as Next Generation Charging.

Those in “inner London” – the original Ultra Low Emission Zone (Ulez) – would have been charged 60p per mile, with a 40p per mile fee applying across the rest of Greater London. It is understood that no final decision on pricing was made.

The London mayor expanded the Ulez in August 2023 to include all 32 of the capital’s boroughs. Most non-compliant vehicles are charged £12.50 daily under the rules.

The Project Gladys modelling also suggests that 600,000 fewer car trips would have been made under the policy, replaced by 170,000 extra bus journeys and 210,000 trips made on foot.

Officials expected that the remaining 220,000 road journeys would “simply evaporate”, London Centric claimed.

The documents set out a roadmap for implementing the pay-per-mile scheme. Following an initial trial, public consultations would have taken place throughout 2024, and London signage would have been replaced in 2025 – with drivers charged by the mile from September 2026.

It is understood that Mr Khan backed away from the proposals after the Uxbridge and South Ruislip by-election in July 2023 was won by the Conservatives who ran an anti-Ulez campaign.

The Telegraph revealed in April that Mr Khan had already spent £3m of taxpayers’ money planning a future pay-per-mile charging system called Future RUC.

Nine Labour-run London councils have voiced support for pay-per-mile or road user charging in recent years.

Sir John Armitt, the Government’s infrastructure tsar, said last month that motorists will “inevitably” end up paying per mile to drive on Britain’s roads as the switch towards electric cars drains away fuel taxes.

A mayor of London spokesman said: “Pay-per-mile charging has been ruled out by the Mayor and no such scheme is on the table.”

A TfL spokesman said: “When we consulted on expanding the Ulez London-wide in 2022, we also asked people for their views to help shape the future of road user charging in the capital. 

“We did exploratory work around a number of different policy options including distance-based charging, but such a scheme has not been developed as a proposal in London, and the Mayor has ruled it out.”