Obviously, the relentless expansionism of museums, towards the day when they shove Starbucks and Tesco Metros off the high streets, must be checked at all costs.

University College London has exactly the right approach to the Petrie, which is safely confined down an alleyway, behind a locked door and up a steep flight of stairs: give it an inch and it would soon take over Bloomsbury.

So, in principle, I’m against new museums: you don’t control Japanese knotweed by potting it up in some compost and giving it nourishing sips of Baby Bio.

But there comes a point when a barrel-load of our history is about to go over Niagara Falls. Next year, people will still remember the original form of the fragments littering the rocks below; the year after nobody will be quite clear whether you use an Allen key or a welding lamp to put it all together; a year after that it will be lost in the mist with the swaddling band and the goffering iron.

What are museums for, if not to preserve these treasures of our collective past? So, I have an idea for a new museum.

Of course it will have nothing as messy and backward looking as a collection, thus avoiding conservation and acquisition problems completely.

And in keeping with the spirit of the times, the museum will open with 15% less space than advertised, and in each successive year the space will be reduced by a further 15%.

At the same time, the admission fee will increase annually by inflation plus 3%, with concessions for the deserving poor, and a special admission rate of the normal price plus 7% for the undeserving poor.

The central hall is reserved for the Museums, Libraries and Archives Council, with the spirit of Renaissance, in the form of a golden phoenix, rising from the ashes and flying up into... actually, there’s some scaffolding in the way, I can’t quite see where it’s flying to, but it’s some glorious future.

The best bit will be the late opening in the courtyard. Every Friday night, with baked potatoes, fireworks and hot punch, there will be the bonfire of another quango.