Livingstone nailed his colours firmly to the mast at "Property in the City", a conference organised by Property Week and the Corporation of London. He said: "There is potential for a 60- to 65-storey tower at Bishopsgate."
Local opponents of the goods yard redevelopment have been heartened after the government decided in March to list a Victorian viaduct on the City-fringe site. This will delay the construction of the East London Line Tube extension, earmarked to run through Bishopsgate.
Campaigners now want culture minister Tessa Jowell to give the viaduct more protection, partly to stymie the redevelopment.
The Railway Heritage Society of Great Britain has applied for the whole site to be given a grade II* listing. Martin Foley, a railway historian and society member, said this was essential to protect the viaduct and railway arches.