Be it The Palace of Westminster or Whitehall, both are not fit for purpose. No modernisation, retro fit, or restoration is going to make these workspaces condusive to a modern business environment. So spending £4billion on the wrong building is a complete waste of money.
The voting chamber should remain in the capital, but there is no reason the many Government departments cannot be redistributed to every edge of the UK. Electronic communication means that expensive office space in London is a gross waste of money. The job can be done in the regions, cheaper and equally as efficient.