The total amount of Congestion Charge fees and penalty charge notices owed by embassies and diplomatic missions now stands at more than £60 million.
In January Transport for London figures showed there was £58.1m owed, meaning the debt is growing by almost £1m a month.
Liberal Democrat Leader Caroline Pidgeon says Mayor Boris Johnson has “allowed the unpaid Congestion Charge bill to soar” by not complying with a London Assembly motion calling on him to write to heads of state of non-paying nations and publish their responses online.
Commenting on the escalating bill, Pidgeon said: “Too many overseas embassies are insulting Londoners by evading a charge which everyone else – including the Queen – has to pay if they wish to drive in central London.
“Under Boris Johnson the total amount owed by the embassies and diplomatic missions has tripled and every Londoner is now owed eight pounds.
“Instead of making excuses the Mayor must take real action to tackle this huge loss of revenue and stop this evasion of the Congestion Charge.”
