The question is no longer whether to act, but whether parliament dares to move. There are two choices the board proposes. Both chambers could move out of the palace for the main works, which could last two decades, at a cost, including inflation, of £16bn. The alternative is for the Lords to move out for up to 13 years, allowing the Commons to decant into the upper house. But that option would prolong the overall works programme to as much as 61 years and cost £40bn. Given those numbers, it is hard to see MPs choosing the latter.