The Civil Service is under-performing, with weak leadership, inadequate professional skills and a lack of effective accountability, according to a report.
A survey by the Institute for Public Policy Research - a centre-left think tank - found a culture of "amateurism" still prevailed at the top of Whitehall, with mandarins resistant to modern management methods.
It called for a massive overhaul of the way the Civil Service is run, with the creation of a powerful new head of the service able to sack senior officials who were not up to scratch.
"Despite its qualities, the Civil Service is underperforming in key respects. It is often ineffective in carrying out its core functions of policy design and operational delivery," the report said.
"Too much Whitehall activity is undermined by its inability to work effectively across departmental boundaries; by a narrow skills-base; and under-developed leadership.
"It lacks a strong centre able to think strategically, manage Civil Service-wide change or drive standards up. Performance is poorly managed, and poor performance too often goes unchecked."
The report - based on interviews with 65 Whitehall "stakeholders" including 40 senior civil servants and eight Ministers - said that despite efforts to bring in outside expertise, mobility both in and out of the service remained "limited".
"Amateurism still too often prevails, reflecting a skills gene pool that is too narrow. Management and delivery expertise, in particular, are still lacking," it says.
At the root of the problem, it claims, were the "anachronistic and severely inadequate" constitutional conventions governing relations between the Civil Service, ministers, Parliament and the public.
The report says Ministers could not effectively hold civil servants to account, even though they are accountable to Parliament for the actions of their departments.
At the same time, it said, officials were not in a good position to "resist improper demands, challenge ministerial amateurism or prejudice, or object to the hiring or conduct of special advisers and other political appointees".
The report calls for the creation of a stronger, more centralised executive, led by a Civil Service head who, in consultation with the Prime Minister and senior ministers, would be responsible for appointing and managing the permanent secretaries who run Whitehall departments.
A Cabinet Office spokesman said the report was a "largely accurate account" of the situation in 2004.
"Since then we have introduced a comprehensive package of policies which address many of the issues raised here."