This is a headache for Parliament, rather than the government, but that is not a distinction that will be recognised in what is bound to be a fuss over the cost.
Plans are in hand. The present estimate is that it will cost £3bn. Is it right to spend that much money on it - and is that the right amount of money?
As you head across Westminster Bridge from the Lambeth side, you can see Barry and Pugin's Palace of Westminster on the left, and Hopkins and Partners Portcullis House on the right. The latter, housing parliamentary offices and meeting rooms, was opened in 2001 amid controversy about the fact that the building cost £235m, and that weeping figs had been rented for the atrium at vast expense, etc etc.
Portcullis House looked like a big and ambitious project; it still does; and in my view it was worth the money.
It's not very impressive compared with the Palace of Westminster, though, and it's not hard to imagine how you could rack up £3bn sorting out the latter. Because it is so familiar, it is sometimes hard to see it for the masterpiece of Victorian architecture that it is, all the way from the brilliant formal balancing of symmetry and asymmetry in the arrangement of the whole, to the craftsmanship and details at the finer scale. Not the least of the architects' achievements was the masterly incorporation of the medieval Westminster Hall in the new complex - and all done without the advice of heritage consultants, English Heritage or Westminster City Council...
My view is that as with Portcullis House, this job must be done properly, for the long term, and with the very best consultants that can be found - and that those responsible for justifying the costs should go on the front foot about the importance of the project to the country as a whole, for quite a long and varied list of reasons.
There are two schools of thought on how you pluck a budget figure out of the air for a project of this kind: either (1) set it low, so that at least you get the go-ahead, and field someone thick-skinned to take the flack when the costs escalate later - in the hope that the client will have the grace to say privately later, as that Chinese emperor is supposed to have done, 'thank you for lying to us about the cost, or we would never have done it'; or (2) set it high, roughly on the Micawber principle, with a budget that includes what a QS I worked with many years ago called a 'protection of the innocent fund' - that is, a cunningly disguised but generous contingency sum that ensures that the bottom line remains the same from start to finish.
The commission is potentially a poisoned chalice for whoever is prepared to take it on. No doubt to be procured under EU rules and therefore not immune to going to a consultant team that is cheap rather than one that is good, the project has potential downside for the chosen consultants that is, I am sad to say, enormous. They will have Sir Humphrey-like clients to deal with, and then sneery parliamentary committees; and if anything goes wrong, or the project goes a penny over budget, they will have the Daily Mail to answer to as well.
Whatever they do, they should avoid specifying any large plants.