Tenants with one spare bedroom have had a payment reduction of 14% and those deemed to have two or more spare a reduction of 25%.
Lawyers for the 11 cases say that, unless the families move from their homes into smaller properties, they face building up rent arrears and being forced out any way.
More top news
A frost-free night for most but chillier than previous nights.
The family's art collection may set new records as the most valuable collection ever sold at the charity auction.
Mansfield MP Ben Bradley was warned to take down the "libellous" tweet which made the claim about the Labour leader.