A planning application for a 52-storey tower in London's Canary Wharf designed by Morris + Company has been delayed just hours before it was due to be determined amid fire brigade concerns over safety.
The 172-metre residential skyscraper on Cuba Street would only have one staircase under its current design.
Tower Hamlets Council's strategic development committee had been due to make a decision on the planning application for the 421-apartment building on Thursday evening, with officers having recommended its approval.
But the meeting was cancelled by the council after developer Ballymore withdrew the application following a last-minute intervention by the London Fire Brigade (LFB) earlier in the day.
"We do have concerns that the design submitted does not provide suitable and convenient means of escape and associated evacuation strategy for all building users," the fire service said in a statement on its website published yesterday.
"In buildings with a single escape route, we would expect the developer to have their own fire engineers provide a full review to show the resilience in the event of a fire and this does not appear to have been carried out."
Ballymore said it will now "work closely with the LFB and local authority towards presenting the scheme for planning approval in due course".
Plans for the Cuba Street tower have received media attention in recent days, with fire safety expert Arnold Tarling telling The Guardian: "It is utter madness that this is still allowed."
Under the international building code, which is adopted in the US, buildings taller than 128 metres must have at least two staircases.
However, building regulations in England permit a single staircase for even the tallest buildings if the fire safety strategy is for residents to "stay put" in the event of a fire.
This has become a controversial topic since the June 2017 Grenfell Tower fire in which 72 people died, with the single staircase in that building quickly becoming smoke-logged as the blaze took hold.
The Cuba Street scheme would be two-and-a-half times taller than Grenfell Tower, though unlike the destroyed block it would contain sprinklers. Grenfell was completed before sprinklers were required in high-rise new build blocks in England.
Ballymore said it will provide clarification on the development.
"As part of the planning application for our Cuba Street development, Ballymore received comments from the London Fire Brigade on the day it was going to committee, requesting clarification around aspects of the application," a spokesperson for Ballymore told Dezeen.
"We are more than happy to provide that clarification and will continue to work closely with the LFB and local authority towards presenting the scheme for planning approval in due course," the spokesperson added.
"Like all Ballymore developments, the Cuba Street scheme will be built in full accordance with approved and emerging guidance and British Standards."
The application will be brought back to Tower Hamlets Council once "issues are resolved."
"We are bound by UK planning law and standards when considering a planning application in our borough. Applications must be decided on their planning merits, irrespective of who the applicant is," a spokesperson for Tower Hamlets Council said in a statement provided to Dezeen.
"Comments from the London Fire Brigade were received yesterday, which raise a number of issues that will need to be addressed. The applicant has asked for more time to respond and therefore the item was not considered at last night’s meeting, and will only be brought to committee once these issues are resolved," the council added.
At another Ballymore development named New Providence Wharf in nearby Poplar, more than 40 people had to be treated for smoke inhalation last May after a fire broke out and spread across multiple floors, with two hospitalised.
An LFB investigation found that a failure of the building's ventilation system had caused it to act "like a broken chimney, leading to a potentially life-threatening situation".
Ballymore is also the developer behind the controversial Sky Pool, at Embassy Gardens in southwest London.
Morris + Company declined to comment.
Plans for the proposed Canary Wharf building can be viewed on the Tower Hamlets Council planning portal.
The images and plans are by Morris + Company.