It is impossible in practice to separate the wheat from the chaff, for we would need to rely on the chaff to identify the wheat. The only hope seems to be a large-scale cull, which would send the incompetent to the dole, and the competent into more productive private-sector employment.
Unfortunately, public sector workers and others who benefit from a bloated government would turn out in force to oppose any party that made specific commitments for large-scale cuts. Each additional public sector worker adds a negligible amount to our tax bill, but for the worker the job is vitally important. The lion runs for its dinner, but the elephant is running for its life.
So we find that mainstream politicians seek to appease the private sector with tough talk about fighting bureaucracy, but they are never specific, and the rhetoric is quietly betrayed. The state gets larger and larger.
In a speech on 12 January 1995, Gordon Brown said
The biggest question ... is why our constitution is over-centralised, over-secretive and over-bureaucratic and why there is not more openness and accountability ... The real alternative is a bonfire of the quangos and greater democracyThe bonfire never came. Instead, New Labour has presided over a staggering expansion of government spending. Even before the bailout of the banks, David Craig estimates that government spending increased by 55% — a total outlay of £1 trillion more than if spending had been kept at 1997 levels. This money has not bought a commensurate improvement in public services, but it has accustomed an ever larger portion of the population to state dependence.
According to the Office for National Statistics
Public sector employment fell every year between 1991 and 1998, reducing by 816,000 in total. Between June 1998 and June 2005 public sector employment rose by 680,000 to stand at 5,846,000,13.2 per cent higher than in June 1998 If the trend continues, we will find ourselves beyond a point of no return. It is not inconceivable that a majority of the population could depend for their livelihood on the state. The revenue-generating minority would then be powerless to stop their continued exploitation.
Of course, our first-past-the-post electoral system means that those dependent on the state need not even form a majority. After all, the past three Labour governments have led us ever more quickly down the road to ruin with the consent of less than half of the population (43.2% in 1997; 40.7% in 2001; 35.3% in 2005).
It would seem that our only hope lies in the dishonesty of our politicians: that one day a leader will come along who cuts the size and cost of government much more radically than the electorate were led to suspect.
 Trends in public sector employment. Labour Market Trends, vol 113, no 12, pp 477-488.ISSN: 1361-4819.
The document notes that June 2005 levels were "still below the levels seen in 1991". I haven't been able to find data for before 1991, but it would be interesting to see. Improvements in information technology should mean that ever fewer administrators are required to manage public services. It is truly worrying that we seem to be heading in the other direction.