Announcing a wide-ranging review, Harriet Harman, Secretary of State for Social Security, said she was looking for "substantial and sustained improvements" in the agency's performance which has been subject to criticism since it was set up.
She said that half a million extra maintenance assessments must be completed by the end of the year and there should also be extra phone lines, some of them for out-of-hours calls, to ensure a more prompt service for callers and better accuracy of assessments.
"Children whose parents are living apart are often worse off. To tackle this we want to help lone mothers to work and ensure that fathers do pay their fair share through the CSA," she said. "Making child support work is crucial to improving the standard of living of children in Britain. We will help lone mothers to work and we will ensure absent fathers pay."
She said the previous government's failure to set up an effective agency with clear objectives had produced an "explosive cocktail" of dissatisfaction.
A CSA spokesman said: "The agency welcomes the further commitment that has been given to the principle that absent parents take proper financial responsibility for their children and that it is unacceptable for them to attempt to evade this liability."
He conceded that there were "too many justified complaints" about the CSA's standard of customer service, and it was taking a number of initiatives, including revising the arrangements for handling complaints and aiming to clear its backlog of cases in the next two years.
The National Council for One Parent Families welcomed the review into the functioning of the CSA. Its director, Karin Pappenheim, said: "We hope this review signals a new determination by the Government to create a fair deal for the many lone parents still waiting for child maintenance.
"Those lone parents and their children are looking to the new government to deliver the effective and reliable maintenance system they need. We urge ministers to stand by the principle of `children first'."
Peter Lilley, the former social security secretary who oversaw the formation of the CSA, called for greater detail on the Government's reform.
"We shall be demanding of them, specification of what they do mean. Do they propose to change the formula? Or do they now suddenly say, `Actually, when we said fairer, we weren't referring to the formula at all. We intend to leave it unchanged'?" he said.
`I just want a fair settlement'
Louise Ryan's husband left her just after the birth of their second son and over the 11 years since she could count on her fingers the amount of maintenance payments her former husband has made.
Having fought to get some money through the courts - which resulted in a couple of payments - her initial reaction to the creation of the CSA was "hurray". It isn't any longer.
"I'm on family credit so I have to respond to anything they send me within 14 days otherwise they cut my benefit, but you can't get answers off them," she said in frustration.
Before the CSA her ex-husband had occasionally paid pounds 40 a month to her and then the CSA said he should pay pounds 9 a week for his two sons now 11 and 12. Ms Ryan said she had about five payments before her husband disappeared again.
She feels the CSA is hardly rushing to rectify the situation: "Then in March they sent me a letter saying it was a two-year review and again I had to respond within 14 days. I haven't heard anything since.
"No one is making my ex-husband responsible for his children. I'm working, but I can't earn enough to get off family credit. I get pounds 9 a week for them because they reckon he earns pounds 161 a week, which after all his expenses only leaves him pounds 19 to split between me and the other family he also left.
"But if I want a review they say I have to give a reason for it. But I have no entitlement to know where he is or how much he's earning and I can't appeal without reason.
"I just want to have a fair settlement. People have got to accept their responsibility if they have children. If he paid me half what I earn I could get off family credit and get off benefits and not be a burden to anybody."
Men angry over double standards
"Harriet Harman should talk with a few of the men and women who have actually had to deal with the agency and then she'd very quickly find out what the problems are, " said Bob Drake.
Mr Drake says that every time a brown envelope arrives from the CSA it is like a "volcano through the door".
His wife left him four years ago and in the last 12 months he has had 14 different assessments. He says the experience of dealing with the CSA has left him "devastated".
"My wife had an affair and eventually left me and now lives with her new boyfriend. He earns a lot of money, more than pounds 30,000, but his wages are not taken into account, whereas if I formed a new relationship my partner's would be. I feel the CSA are operating a dual standard."
He pays his ex-wife pounds 380 a month for his two children aged nine and 11: "I'm trying to survive on the little money I have left ... My 17-year-old son (from a previous relationship) lives with me and I know he has a lower standard of living than they do."
"The agency controls every aspect of my life. I live in the former marital home which I would like to sell but new lenders go very quiet once they hear the agency is involved. Every time my ex-wife phones up the agency to say she thinks my salary has gone up I get a new assessment. Last October they chose to do an assessment in a month when my car allowance was listed plus I'd worked an awful lot of overtime and they reassessed me as if that was what I was getting every month.
"The worst thing about this is the effect on the children. When I had access days I couldn't afford to take them anywhere. It's not been fair on them".Reuse content