Landlords who break the law by exploiting their tenants should have their properties confiscated, a committee of MPs has concluded.
Members of the Housing, Communities and Local Government (HCLG) committee said vulnerable tenants needed greater protection.
Many face retaliatory evictions, unfair rent increases and harassment.
During its inquiry, the committee heard that up to 25 people could be found living in three-bedroomed houses.
It also found landlords who charged tenants up to £500 for a bed in a room with four bunkbeds.