The United States Embassy in London refuses to pay the £8 (US $14) "congestion charge" imposed on anyone entering the city with an automobile by London Mayor Ken Livingstone. Under international law, diplomats are not subject to the taxes of foreign governments and Ambassador Robert Holmes Tuttle thinks the congestion charge is really a tax.

"It's the view of the United States government that all direct taxes on diplomats and diplomatic operations, including this one, are prohibited by the Vienna Convention," embassy spokesman Susan Domowitz told USA Today.

Embassy staff stopped paying on July 1, when London raised the fee from £5 to £8. At the lower rate, the city was taking in £540,000 daily from the charge itself on top of £660,000 from tickets given to those who had forgotten to pay, for a total daily revenue of approximately US $2.1 million.

Mayor Livingstone counters that the congestion charge is not a tax because entering the city by automobile is optional, and that the ambassador should take the bus if he does not want to pay the £8 charge. A one-day Transport for London travelcard is available for between £6 and £13.20 depending on the distance traveled.