The Prime Minister said he was considering measures to persuade or compel public bodies including Network Rail to release thousands of pockets of under-used land for homes.
His thinking is driven by his observations on the election campaign trail and his experiences as Mayor of London.
“One of the things you’ll remember when I was Mayor was the frustration of having all these pockets of land everywhere, whether owned by Network Rail, the NHS, the MoD.”
“They are not allowed to make as good use of them as they might by the Treasury rules. I want to eradicate homelessness not just by helping the homeless but to do something to tell them to build more homes: an active intervention.”
Mr Johnson wants to change Treasury rules so that public bodies get bigger benefits if they let go of unused land, which can then become a housing site.
“There are a lot of things you need to do together. It’s not just ‘no second night out’ but ‘housing first’ and making sure all the agencies that look after homeless people are fully joined-up.”
The Tory manifesto has committed to ending rough sleeping by 2024.
On his experiences of sleeping out in London in support of the previous Standard campaign, Mr Johnson recalled “the experience of waking up in the small hours on a very hard cardboard matt, looking up at the stars and wondering why you’re there.”
He added: “It is not good enough for people to go through this. We need to tackle it — and we will.”