There are two issues. There is clearly some dirty money; it would be naive to suggest there is none. That said, there is also significant investment from Russia and the middle east that is not dirty money at all. As for offshore companies, we should not necessarily assume that there is a direct connection there. There is a range of reasons for using offshore financial vehicles in an entirely legitimate way. The important thing is to have a registration process—although it need not necessarily be open, because that would lead to all sorts of other difficulties—so that the authorities in the Channel Islands or Cayman Islands, for example, are well aware of what is going on.

I appreciate that others want to speak but want briefly, if I may, to suggest some qualifications that we might have in mind as criteria for purchasing into the London market. An individual should be either a British citizen or permanent resident, and the purchase should not be for a buy-to-let investment, but a home to live in.

It should be possible to let the property out only after period of residency, and then only for a specified time before it would need to be sold. If the property were immediately sold, a penal capital gain would be levied, and it would have to be sold to people who qualified under the same criteria. Additional levies on speculative ownership and buy-to-leave-empty purchases might also need to be considered alongside a potential system for a higher non-resident council tax, which I have also discussed in the past.

I am trying here to provoke some thoughtful debate, and I recognise that some of my proposals will not necessarily prove entirely practicable. However, we should not lose sight of the foundations on which the high property prices in London are built. They have much to do with the huge amounts of social capital created by our constituents over many centuries. We are custodians of that social capital, and our duty is to grow it, improve it and bequeath it properly to future generations.