There's a hint there, for Luton people who think they might be homeless soon. Make a good case to the London Councils of why you're actually homeless in London. Then, they might just send you to Luton!
You don't have to be sleeping rough to be homeless. You are homeless if you don't have any right to stay where you live or if your home is unsuitable for you. Anyone expecting to be made homeless should make arrangements, fast. The best place I know of to start looking for advice is at Shelter.