The report, by Her Majesty's Crown Prosecution Service Inspectorate (HMCPSI), calls for all charges supported by sufficient evidence to be pursued to conclusion - as long as it is in the interest of the public.

Every year the police record millions of crimes for which offenders are never brought to justice.

By 2006 the government wants to reduce what it calls the "justice gap", with 1.2 million extra cases resolved every year.

It is important all agencies work vigorously together Stephen Wooler HMCPSI

But the HMCPSI report reveals 13% of the Crown Prosecution Service's cases remain unresolved.

A third of these relate to traffic offences but one in five relates to assaults and a further fifth (22%) involve theft or fraud.

The inspectors admit there are some cases which are not in the public's interest to pursue - because the defendants have been sentenced for more serious crimes or are already behind bars.

Press charges

But they want other cases followed through to conclusion.

And the report calls for prosecutors to work more closely with the police.

HMCPSI's Stephen Wooler said: "It is important all agencies work vigorously together."

And director of public prosecutions Sir David Calvert-Smith QC said pilot schemes had already begun to give police better advice about when to press charges.