Two commuter bus routes serving Waterloo and London Bridge stations will from next year be operated entirely by electric vehicles, Mayor of London Boris Johnson has announced.
Two Chinese-built electric buses have operated on the routes since 2013 and a further two buses from Spanish firm Irizar have this month joined the fleet.
At Mayor's Question Time on Wednesday Mayor of London Boris Johnson revealed that all diesel buses will be withdrawn from two routes next year.
"I can announce today that we are stepping up our electric bus fleet by introducing a further 51 all-electric vehicles in the autumn of next year on routes 507 and 521," said Mr Johnson.
"That means there will be over 70 zero tailpipe emission vehicles in the capital in just over one year's time.
"There are currently 10 vehicles in the fleet. That will grow to 17 in September and 22 in October when the first double deck electric bus ... arrives on our streets.
"By 2020 all 300 single-deck buses operating in central London will be zero emission – either electric or hydrogen – and all 3,000 double-deck buses in central London will by hybrid."