Political business in Westminster has been disrupted after a crane collapsed on to the roof of the Cabinet Office during high winds of the St Jude's storm.
The equipment fell on the Whitehall building early this morning.
The building was evacuated, and surrounding streets cordoned off, but no injuries have been reported.
TOP NEWS STORIES TODAY
Deputy Prime Minister Nick Clegg was due to hold his monthly press conference in the building this morning, but has warned journalists not to make the journey in.
A Cabinet Office spokeswoman told ITV News: "As is the case with many other buildings in storm-affected areas, and despite the necessary preparations, there has been some damage to the Cabinet Office building.
"A crane at the back of the Cabinet Office was dislodged by the storm, and is currently resting on the roof.
"We are assessing the damage, and the building has been evacuated while we do so.
"Many staff can log on and work flexibly from the Treasury building or from other locations and we are exploring other temporary options.
"We are working hard to ensure the safety of our staff and minimum disruption to operations."
Elsewhere in Westminster, the Prime Minister chaired a conference call with government departments and agencies on plans to protect people from the storm.
Transport ministers, the Department for Communities and Local Government and the Cabinet Office updated Cameron on preparations and contingency plans for transport, local authorities, schools, health and power supplies.
He was told that the storm could have a widespread impact but plans were in place to respond, a spokesman said.