BusinessGreen: The business case for buying electric vehicles in London became even stronger yesterday, after the Mayor of London announced plans to make all diesel vehicles pay the Congestion Charge. Transport for London (TfL) confirmed it will replace the existing Greener Vehicle and Electric Vehicle Discounts with a stricter Ultra Low Emission Discount (ULED) from July 1. Cars currently qualify for the Greener Vehicle Discount if they emit 100g/km of CO2 or less and meet the Euro 5 standard for air quality,...