The last time the Tories proposed this sort of thing, under William Hague more than twenty years ago, it was estimated it would take £850m to build the detention centres and another £220m a year to run them. We can probably double those figures to bring them up to date. On top of that, every person sent to Rwanda costs £600,000. Soon all this adds up to serious money. I'm sure there must be more intelligence led ways to achieve the same thing, a lot more cheaply, without needing to detain every asylum seeker.