MPs Simon Hughes and Kate Hoey have lent their support to the campaign to keep the Routemaster bus on London's streets and joined a demonstration outside City Hall.
"The Routemaster is extremely popular with both drivers and passengers," said Simon Hughes. "It is a successful London icon and should continue to play an important part in London's public transport network.
"A decision to run down the Routemaster should not have been taken by Ken Livingstone and his advisers without a proper consultation of Londoners. It is time to recognise all the benefits of the Routemaster model and plan to build a new generation of this popular bus."
SE1 will say farewell to the Routemaster when the vehicles are withdrawn from route 159 (Marble Arch to Streatham via Westminster Bridge) on 9 December.
Two new tourist services using preserved Routemasters start in November, but despite a campaign by London Lib Dems neither route will come south of the river.