The issue of empty homes has been raised again, this time by campaigners in Islington.
They've called on the Ministry of Justice to free up a block of flats near Pentonville Prison, which they say have been left empty for decades.
The local council says it should be given control of the building, to rehome some of its 800 homeless families, currently living in temporary accommodation.
The Ministry of Justice says it was unable to give us an interview during the election campaign, but here's part of that letter they sent to the campaigner we saw in that film:
“The flats are located close to the perimeter wall and letting them out to non-HM Prison and Probation Service tenants would pose a security risk. We have had discussions with Islington Borough Council in the past about the possibility of leasing the flats. However, security concerns, along with other factors including consideration of the possibility of extending the perimeter wall to incorporate the flats, were prohibitive in agreeing a way forward."