Billions of pounds are being wasted by government departments which have failed to learn the lessons of the past, a Commons committee has warned.
The committee examined its reports from the past decade
"Basic errors are repeated time and again," the Public Accounts Committee said, adding public services were marred by complexity and bureaucracy.
A 2% improvement in their spending could save £8bn a year, it argued.
The report comes a day after the chancellor hailed improvements in the public services in a pre-Budget report.
Gordon Brown told MPs the government had been investing more and getting taxpayers better value for money.
But the report by the influential committee of MPs paints a picture of waste and mismanagement.
Chairman Edward Leigh said that despite "fine words" and "earnest assurances" to his committee, departments had failed to learn from each other's experiences.
"Many public services are marred by deadening complexity and bureaucracy.
"There is a continuing lack of leadership and drive. And government departments still disregard common and well-publicised pitfalls when they approach projects," he said.
According to the committee's 17th report on achieving value for money in the delivery of public services, there has been too little progress over the last decade.
Improvements were not materialising or were taking place too slowly in many areas, it said.
And there was a failure to apply more widely the lessons learned in one part of the public sector, it added.
Mr Leigh concluded: "If one lesson stands out from the world of the Public Accounts Committee over the years, it is that government departments are masters at spending money but often far less proficient at ensuring this translates into better public services."
The committee urged government departments to plan more carefully before implementing projects and to strengthen project management.
Complexity and bureaucracy should be reduced and public service productivity increased.
It also urged departments to be more commercially astute and tackle fraud.
The committee based its comments on analysis of a sample of its own reports going back to the early 1990s.