"On Monday the situation changed for us because we are now in the congestion charge zone, " the diplomat told BBC News.

BBC: NEWS | UK | England | London | Embassies suspend paying C-charge

Critics of the scheme say it will unfairly penalise commercial vehicles that need to move in and out of the charge zone several times a day.

BBC: Colt gets London car toll contract

TfL said from July 2013 electric vehicles and cars that comply with much tighter emissions standards would receive an Ultra Low Emission Discount, earning free entry into the congestion charge zone.

BBC: Congestion charge greener vehicles rule change planned