About 1m vehicles will be hit by a new levy to drive in large parts of London that is expected to raise up to six times as much as the congestion charge.

The “ultra-low emission zone” (ULEZ) fee of £12.50 a day will be a financial lifeline for Transport for London (TfL), which faces a cash crisis after the mayor, Sadiq Khan, froze fares and the government cut its grant. It will collect between £700m and £1.5bn a year from motorists. The congestion charge raises £230m.

“This could be Sadiq’s poll tax,” said Gareth Bacon, leader of the Conservative group on the London assembly. “It has flown under the radar and people do not know what is going to hit them.” Referring to protests against