The tower at 1 Undershaft in the City would be 309.6 metres (1,016 ft) high, matching the highest point of the Shard and replacing the existing 118m (400 ft) Aviva Tower, formerly the Commercial Union Building.
It has been designed by Eric Parry Architects and is being developed by Singapore-based Aroland Holdings.
Among its features will be the highest public restaurant in London and a viewing platform that is loftier than the one in the Shard.
There will also be a public square, based on suggestions made in a public consultation.
Although the Square Mile has seen several new skyscrapers rising in recent years, London's tallest building has been elsewhere in the capital since One Canada Square was built at Canary Wharf in 1991.
