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 10 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.
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Savers into the new scheme can expect rates as high as 4 per cent from some banks.
Very windy with gales possible
Strong performance from world number 100 meant Great Britain very nearly dominated day one of the competition.