A long-delayed Child Support Agency system designed to simplify maintenance assessments is to be introduced in March, the government has announced.

Work and Pensions Secretary Andrew Smith said he was now satisfied the new system, which was originally due to come into effect in April 2002, would "deliver a level of service our customers have the right to expect".

The new IT system is key to bringing in the much needed child support scheme with its better, fairer, simpler system of calculating maintenance Andrew Smith

The new formula, designed to be an improvement on its much criticised predecessor, uses a simple percentage rate of maintenance payment - based on 15% of the absent parent's net income for one child and 20% for two children.

Mr Smith told MPs in a statement: "Implementation of the new IT system is key to bringing in the much needed child support scheme with its better, fairer, simpler system of calculating maintenance.

"It will help us target resources to make sure that more maintenance is actually paid, getting more money to children more quickly."

Extra costs

The agency was now "more customer focused" and was collecting �200m more each year in child maintenance than it was five years ago.

"Both my senior officials and I are now satisfied, on the basis of the careful and comprehensive testing, that the system will deliver the level of service our customers have the right to expect," said Mr Smith.

Mr Smith told MPs the government's share of the bill had gone up by about 7% over the term of the contract.

"While any extra costs are unwelcome, an increase on this scale is not at all unusual for a complex project of this kind and is justified to deliver this important reform," he said.

'Relief'

Mr Smith said his predecessor Alistair Darling had taken "the right decision" in announcing last March that the new scheme would be delayed until the government was confident the new IT was "working effectively".

David Willetts, the shadow work and pensions secretary, welcomed the announcement "with some relief after years of delay".

But he said EDS, which built the new Child Support Agency computer system, had blamed interference by ministers for the delay.

"We know the government is going to pay more as a result of this delay - that implies the government accepts some responsibility for what has happened," he said.

Liberal Democrat spokesman Paul Holmes predicted the announcement marked only the start of the "next shambles".

Mr Holmes said the new computer system was postponed in 2001 because it could not cope with working out simple sums about people's income.

He asked: "How will it cope with a sudden flood of information when the one million existing cases are transferred to it?"

Percentage system

From 3 March new CSA cases will be calculated using the new rules and will come onto the system at a rate of 30,000 a month.

The existing 1.1 million cases will be moved on to the new system when it is clear the arrangements are working.

Under the new rules, absent parents with net incomes of �200 to �2,000 a week will be expected to pay about 15% for one child, 20% for two and 25% for three or more.

For those parents with incomes of less than �100 a week, maintenance will be set at �5 a week. For those earning between �100 and �200 a week there will be a sliding scale.