The breakdown of a family can be one of the most painful forms of heartache to bear, where the need for cool and calm thinking can often be absent at a time when it is needed most.

Too often the issue attracts easy headlines about feckless dads walking out on their children, and obstructive mums thwarting a dad's effort to play his part. Yet very often the truth is much more complicated.

Writing in a Sunday newspaper to mark Father's Day, the prime minister entered the debate with a rebuke against absentee dads, adding that while the government could do nothing to force fathers to get involved in their children's lives, it could make it easier for them to do the right thing than the wrong thing.

But beneath headlines, the government's approach is rather different and not just aimed at absentee parents.

Among the raft of reforms being undertaken by the coalition government, one which may have slipped beneath the radar, is its replacement of the Child Support Agency (CSA) with the Child Maintenance Enforcement Commission (CMEC).

In fact, mums and dads standing either side of the divide in any family break-up may soon become aware of what is involved because the government is proposing to charge parents who make use of the new agency to help with organising payments.

Ministers hope most parents will sort things out themselves either on their own or with the help of their own lawyers. But where they have to turn to CMEC for help, the commission will charge those parents, where it has to formally help out, with the burden of proof placed on the parent making a claim to show that he or she has already taken 'reasonable steps' to try to sort things out.

The government is still consulting on the exact amount of fees to levy which could range between 7pc and 20pc of any maintenance amount, with reduced amounts for those on benefits.

But to give a flavour, if CMEC determines that a dad must pay �100 a month in maintenance, the actual amount paid with the fee could be �120, while the mother could only receive �88.

Critics believe that the charges, which would also see an up-front fee for getting CMEC involved and an ongoing slice deducted from any payments, are a tax on both parents.

Some fear the main 'resident' parent, usually the mum, could be hit hardest, while fathers' groups believe that the charges discriminate unfairly against the absent parent (usually the dads), who face a higher levy.

But supporters believe the changes will help bring to an end to the situation where one parent has used the CSA as a weapon against the other, by forcing both parents to sit down and try and work things out. It will also cut costs at a time that the government is trying to reduce the deficit, which is believed to be a key driver behind the proposals.

In Norfolk, the CSA has more than 15,000 cases on its books, but there has already been a shift towards the new collaborative family-based arrangements with more than 100,000 parents nationally now signed up.

Christine Parish, a CMEC child maintenance options consultant based in Norwich, said: 'Often the most important discussions separated parents need to have are about money and how their children are to be supported. I always encourage parents to first explore with their ex-partners the possibility of agreeing child maintenance between themselves. If they are unable to do that, there are other routes they can take, but if they are on speaking terms it is well worth having that discussion. Reaching the 100,000 milestone shows how the support we offer at Child Maintenance Options helps so many parents to resolve matters themselves.'

Iain White, a family lawyer at Cozens Hardy in Norwich, said many lawyers were still waiting to see how the changes would work in practice.

'We really don't know how this going to work, but it's difficult to see anything being worse than the CSA,' he said.

'If parties can agree things, that has several benefits and also saves bureaucracy,' he added. 'People tend to be more accepting of something they have both had a part in and have got some investment in rather than something that's fed upon them from above.'

Jane Ahrends, spokesman for Gingerbread, the campaign group for single parents, said there were fears the government was overestimating the numbers of people willing to use the new system, and the charges could deprive children of much-needed money. 'There are lots of reasons why people cannot come to their own arrangements and, if there is a conflict, it can be very difficult,' she said. 'Often the parent with care can feel that it's helpful to have the shadow of the agency behind them. There is a hard core, of mainly non- resident parents, mostly dads, who aren't willing to pay their child maintenance.'

But she feared that some parents would be tempted to give up seeking maintenance rather than pay to get CMEC involved. 'It's money that can make a big difference to a child's life,' she added. 'What we are hearing when we speak to single parents on our helpline is that some of them will have to do without the money.'

Ken Sanderson, chief executive of the family-support group, Families Need Fathers, broadly welcomed the new approach but said it needed to be able to take into account individual circumstances.

'We feel that the changes for child maintenance is probably a good thing to do,' he said. 'In the current financial climate, changes have to be made, but the big flaw is the differential in charging; what they are suggesting is that the non-resident parent pays approximately double what the resident parent pays. To us that's saying there is some blame being attached.'

The government also believes the changes will 'incentivise' people to make their own arrangements.

Work and Pensions minister Maria Miller said: 'We want separated families to have the right support to work out their own child maintenance arrangements without the state getting involved.

'The figures show that with the right help, parents can come to their own family-based arrangements. We want to build on the support provided by Child Maintenance Options to help many more children in separated families – including the huge numbers who do not currently benefit from any child maintenance at all.'

shaun.lowthorpe@archant.co.uk