A NORTHWICH mum will sue the Child Support Agency after she claims it miscalculated the amount she was owed in maintenance payments from her ex-husband.

But mother-of-three Alison Davies is trying to extend the grounds on which she can sue the CSA.

Judge Philip Hughes, sitting at Warrington County Court, allowed the 43-year-old the right to take the case to trial in the area of special reliance.

Now Alison wants to gain a legal ruling that the CSA has a duty of care to those it works with, in the same way doctors and solicitors do.

She said: "The area of special reliance is if you rely on someone to do something and they don't do their job properly - then you can sue them but you've got to prove you totally rely on them.

"I want to move this forward to negligence in the area of duty of care, which doctors or solicitors have.

"We should establish duty of care for the CSA because they're dealing with people who are very vulnerable - they've just split up with their partner, have children to bring up, have no money and have to deal with this organisation that should just do their job properly."

She added: "If they had a duty of care and were made more responsible they would be more careful."

Alison's legal battle began after she split from her husband, Michael, in 1998 and applied for child support when she took custody of their three daughters, now aged 12, 13 and 16 years old.

She alleges that the CSA failed to take into account the income her ex-husband was receiving in rent for a garage, as well as his earnings from employment, which meant that he did not have to pay anything.

If her appeal is successful it will pave the way for thousands of similar claims.