Green's report into government efficiency, which was published today, found that the prices paid by government for commodity purchases are often far from competitive.

He identified the lack of a centralised approach to buying goods and services, which has failed to leverage the buying power of the public sector and resulted in departments paying hugely different prices for the same items.

The capability of print buyers varied greatly across government departments while buying processes were often inconsistent, the report said.

Green added: "There is no reason why Government should not be as efficient as any good business.  Any large organisation would want to use its credit rating and scale to buy efficiently. 

"The conclusion of this review is clear - credit rating and scale in virtually every department has not been used to make Government spending efficient."

Among his recommendations to the government, Green advocated centralised procurement, the production of accurate spend and consumption data, managing down demand and specifiations, and pricing common items at the same level for all central government departments.

The minister for the cabinet office, Francis Maude, who commissioned the report, said: "The scale of the waste uncovered by Sir Philip and his team is staggering. We know that Government is very different to business.  But that does not mean that it should not act in a more business-like manner.  

"Every pound that we can take out of the cost of government is a pound we can protect on the front line. Our over-riding aim is to protect the quality of front line services and to protect the jobs of dedicated public sector workers."