The Prime Minister urged the courts yesterday to make more use of tough sentencing powers available for gun crimes.

Gordon Brown said the “mandatory” minimum jail term of five years for possessing a firearm, introduced four years ago but still not being enacted fully, was part of a range of tools available to clamp down on gun criminals.

Mr Brown was responding to calls from a senior police chief for judges to be consistent in imposing the five-year term set down in law.

Bernard Hogan-Howe, the Chief Constable of Merseyside, told The Times that heavy sentences were an essential part of the strategy to deter criminals from carrying guns. He said: “There is evidence of sentencing where the power has been available and not been used and that is simply wrong. I want very heavy sentences for possession of firearms which would deter people from arming others or carrying guns themselves.”

But the judiciary defended its interpretation of the sentencing powers and the right of judges to use their discretion.

A spokesman for the Judicial Communications Office said there was a proper legal mechanism for the police and others to complain about supposedly lenient sentences.

He added: “If, in any individual case, the police or the Crown Prosecution Service believe that a mandatory minimum term has not been imposed for gun crime for reasons that are not justified, it is open to them to ask the Attorney-General to consider referring the case to the Court of Appeal as unduly lenient.

“This provides a clear mechanism for sentences to be reviewed and checked against the statutory framework, sentencing guidelines and case law. The number of cases referred for failure to impose a mandatory minimum sentence is small.”

But Mr Brown said it was vital that other elements of the criminal justice system backed the police in the fight against guns. “The important thing about gun crime is that we have the policing and support for the police to enable us to root out gun crime,” he said.

“We had set sentencing that is very high — five years for possession of a gun — for \ to use. It is tough sentencing, to take action alongside more policing in hotspots, more metal detection, more undercover policing, more stop-and-search powers and more surveillance.”

However, Chris Huhne, the Liberal Democrats’ home affairs spokesman, said there was an “increasing gap” between what the Government said about penalties and the sentences that judges handed down.

Mr Hogan-Howe had the full backing of the Merseyside Police Authority for his stance. Rose Bailey, a member of the authority and councillor for the Croxteth ward where 11-year-old Rhys Jones was shot dead in August, said: “I don’t think the message is being driven home. If anyone is minding or in possession of a firearm, temporarily, on behalf of someone, or whatever . . . If there is a gun in their possession they know is going to be used for criminal activity, then they should also get the minimum mandatory sentence.”

The Times revealed a number of cases in recent months where judges had imposed terms below the five-year minimum. The Home Office admitted that the average sentence for possessing a firearm was less than five years. A spokesman said: “We have set in place tough legislation but it is appropriate that sentencing is ultimately a matter for the courts.”

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