More than 500 extra workers will be drafted in on the Heron Tower construction site over the coming months as the project continues to progress.
The steel skeleton for the tower is now more than halfway complete, with construction of the 46-storey building having reached level 24.
Project director Gary Clifford said there were currently 300 workers at the site. This number is set to peak at 800 in November and the skyscraper is expected to top out in March next year.
When completed in 2011 the Heron Tower will be the tallest building in the City of London, standing at 202m with a radio mast climbing a further 30m higher.
Last week a time capsule, containing various items of significance to the project, was sealed into the foundations to mark the bottoming out of the tower.
Among the items placed in the capsule was a tortoise shell which it is hoped, as part of feng shui traditions, will bring luck to the building’s future tenants.