The scheme was introduced natinwide in 2016
The Telegraph article which I think is one of your various sources states
Housing migrants in private accommodation is cheaper than hotels, costing as little as £14 per night compared to around £145.
The use of landlords was first introduced by the Conservatives more than a decade ago. It is being expanded under Labour as the Government faces a growing number of migrants crossing the Channel and seeks to end hotel use.
The landlord drive is targeted at HMOs – houses in multiple occupation – family property, former care homes, residential and student accommodation.