The U.S. Embassy in London has failed to pay more than $3.9 million in traffic congestion charges, according to figures published Thursday by Britain's foreign ministry.
British lawmakers condemned U.S. diplomats, after they topped a list of embassies refusing to pay the charge.
The list of fees owed by embassies showed that the United States refused to pay the levy 23,188 times between February 2003 and last month.
Japan has racked up the second largest amount of outstanding fees, owing more than $2.6 million.
With the congestion charge, drivers must pay $16 per day to drive in central London during business hours.
"This is a perfectly proper charge and the failure to pay such a huge amount is not only extremely discourteous to the people of London and the country as a whole, but is undermining U.K. domestic transport policy," opposition Liberal Democrat lawmaker Norman Baker said in a statement.
Ambassador says it's a tax
U.S. Ambassador Robert Tuttle claims the toll is a tax. Since diplomats are exempted from paying local taxes, he argues his staff shouldn't have to pay the levy.
Former London Mayor Ken Livingstone gained widespread media attention in Britain by calling Tuttle "a chiseling little crook" over his refusal to pay.
Japan's Embassy said in a statement Thursday that its staff members and their families are only required under international law to pay charges, dues or taxes for services rendered and that the congestion charge does not fulfill that requirement.
The levy was introduced in 2003 in a bid to reduce traffic, cut greenhouse gas emissions and encourage people to use public transport.
New York City Mayor Michael Bloomberg tried to introduce a congestion charge there, but state legislators refused to approve the plan.