An eight-month probe by MPs into government computer systems has found an "appalling waste of public money".
The Child Support Agency is once again in the firing line
There needs to be greater openness from ministers about the projects says an influential Commons committee
Singling out the Child Support Agency for particular criticism the MPs said the CSA's phone and computer system was "over-spec, over budget and overdue".
Work and Pensions committee chairman Archy Kirkwood said improving IT projects would bring huge benefits.
The MPs also accused Whitehall departments of "hiding behind the cloak of commercial confidentiality" and failing to provide "legitimate information" about IT schemes.
Lib Dem MP Mr Kirkwood said: "Failing IT
systems are an appalling waste of public money and cause distress to thousands of people.
"Improving the success rate of IT projects would produce enormous benefits
for clients, taxpayers, Department of Work and Pensions staff and IT suppliers.
"Government has produced a mountain of guidance to encourage successful IT projects but there's no way for parliament or the public to know whether it's
being followed - until the IT fails and then it's too late.
"There is an urgent need for more transparency."
The committee said there should be a full "post-mortem" into the installation of the CSA computer system so lessons could be learned.
Costs had risen from £400m to £456m. The system was brought in March 2003 after a two-year delay.