Plans for a five-year minimum jail term for carrying an illegal gun have not been watered down, Home Secretary David Blunkett is insisting.

This is not a matter of watering down the minimum five-year penalty for those blatantly carrying a gun illegally David Blunkett

Police officers attacked the measure as a "waste of time" when it emerged the sentence would not be imposed in all cases.

But the Home Office said judges would only have the same amount of discretion already employed over minimum sentences imposed for repeat offences.

Ministers have also insisted the sentencing plans are not a snap response to the New Year shooting in Birmingham in which two teenage girls died.

Judicial opposition

In a letter to The Times newspaper, Mr Blunkett said: "There have been no U-turns, there has been no backing down and nothing has changed.

Gun related murders per 100,000 population

USA - 4.08 Canada (1999) - 0.54 England/Wales - 0.12 Scotland (1999) - 0.12 Japan (1998) - 0.04 Sunday Times

"Gun crime is a blight on our society and we are determined to tackle this head-on by ensuring a clear message that carrying illegal guns is unacceptable and that sentences given at the moment are too low."

The move to toughen up the gun laws has drawn opposition from senior judges, prompting fears that the proposal could be defeated in the House of Lords.

Downing Street's confirmation that judges would be given a degree of discretion promoted criticism from rank-and-file police officers.

The Conservatives said the policy has become a "mess".

Discretion

In his letter, which was released through the Home Office, Mr Blunkett said: "Judges will retain their historic discretion in sentencing someone to custody for more than the five-year minimum.

Police welcome changes to gun laws

"Nor is anyone seeking to send to prison someone whose authority to hold the weapons has been delayed by a few days.

"But this is not a matter of watering down the minimum five-year penalty for those blatantly carrying a gun illegally.

"Furthermore, mandatory minimum sentences, with the exception of murder, which carries a mandatory life sentence, already carry some element of judicial discretion for very exceptional cases.

"In these cases, judges are always required to explain their reasons in open court."

'Straightjacket'

Some judges fear the mandatory jail proposal will limit its ability to match justice to circumstances.

Lord Ackner, a former law lord, said judges should not be put in a "straightjacket" when it came to sentencing.

Former Master of the Rolls, Lord Donaldson of Lymington, said Mr Blunkett seemed unwilling to trust judges.

Sentencing scrutiny

The Conservatives, however, have accused the government of "kneejerk" reactions - first to the Birmingham shooting and then to judicial disquiet.

Shadow home secretary Oliver Letwin told BBC Radio 4's World At One programme: "This is not the right way to be engaging in sentencing policy."

Mr Letwin argued it was difficult for Parliament to set effective and proper minimum sentencing.

But he said there ought to be new parliamentary scrutiny for sentencing guidelines issued by the lord chief justice.

Police reaction

Liberal Democrat home affairs spokesman Simon Hughes said: "Minimum sentences are wrong in all circumstances. Parliament should fix maximum sentences but it should be for judges and magistrates to ensure that the punishment fits the crime."

The apparent dilution of the firearms sentencing plans has angered some police officers.

David Rodgers, vice-chairman of the Metropolitan Police Federation, said the sentences were not mandatory if exceptions were allowed.

Mr Rodgers said: "It is something which is so awful and if we are going to combat it, why do you need discretion in such cases?"

As well as announcing the sentencing plans, Mr Blunkett attacked violent gangster rap music, condemning it as "appalling".