Council tax support inclusion of child maintenance as income

In search of savings Cotswold District Council have made the decision to fully disregard child maintenance for UC claimants and at the same time overturned their previous position for those on legacy benefits and include in full child maintenance as income.
Using CDC’s figures legacy claimants will on average see £519 a year loss of CTS! These claimants of course are almost exclusively single women with children. Is there a case for arguing this is a discriminatory regulation under Human Rights legislation?
Practically we could campaign to do better off calculations for those affected (183 claimants) and help them apply for UC .
Just seems so wrong council savings being made by taking money away from the poorest residents especially as Cotswolds is the 2nd worst performing LA in the country for youth social mobility according to The State of the Nation 2017 -Social Mobility in Great Britain.
Thanks