Protecting the public is the first duty of any government.

The public rightly expects protection from serious, dangerous or persistent criminals.

In particular, people expect someone who is convicted of a serious crime to receive a suitably severe punishment.

If violent or sexual offenders need to be locked up to protect the public, they should be.That is what underpins the statutory framework for sentencing which the government has put in place.

It is why we have not hesitated to increase maximum penalties in response to public concern about serious crime and why we introduced a power for the Attorney-General to refer unduly lenient sentences to the Court of Appeal.

It is also why we have taken a range of measures to toughen and strengthen community sentences.Imposing proper punishment and, in the most serious cases, severe punishment, is vital if public confidence in the criminal justice system is to be maintained.

That confidence is an essential element in an ordered and stable society.

If people are to feel that the law is fair and just and gives them adequate protection, it must meet their standards and expectations.The penalties available to the courts are one part of this.

They contribute directly to the protection of the public, as well as to crime prevention, deterrence, rehabilitation and reparation.

Where there is evidence that the public could be at risk, the government must take action.

That is what lay behind the proposals on sentencing which I announced two months ago.

These proposals have three main elements.First, the public and criminal should know that the court's sentence means what it says - at present, it does not.

The sentence is not backed by reality.

An armed robber can be sentenced to nine years and be out in six.

This is not as a result of any ruling by the court; it is as a result of a law passed by Parliament.

If it is to be changed, it is for Parliament to change it.I propose that the sentence imposed by the court should be served in full.

Model prisoners would be able to earn a small discount by good behaviour, but automatic early release would be abolished.

Post-release supervision would still take place, but after the sentence has been served, not during it, as happens at present.Secondly, anyone convicted for the second time of a serious or violent sexual offence would receive an automatic life sentence.

Currently, serious violent or sexual offenders who do not receive a life sentence have to be released at the end of their sentence even if they are still dangerous.

That is indefensible.

In my view, those who commit such an offence a second time should not be released unless and until it is safe to do so.

The trial judge should continue to set the 'tariff' to be served for the purposes of retribution and deterrence.

At the end of that p eriod, the Parole Board would carry out a risk assessment to determine whether it was safe to release the offender.Finally, if prison - and the threat of prison - are to work effectively, there is a strong case for greater certainty in sentencing.

Those who are contemplating crime should know what to expect if they are caught and convicted.

Persistent burglars and drug dealers bring particular misery and fear to the community.

They should know that they face stiff prison sentences if they continue offending.

Accordingly, I propose that courts should be required to impose a minimum prison sentence on offenders convicted of burglary or dealing in hard drugs, if they already have two or more previous convictions for such offences.

The courts would have the discretion to waive the minimum sentence in exceptional cases.Minimum sentences are not new.

They already exist for murder and for drink driving.

In the latter case, drivers know that if they are convicted they will be disqualified.

This has helped to bring about a reduction in the number of offences.None of these proposals would involve any increase in the powers of the home secretary, but they would increase the protection available to the public from serious, violent and sexual offenders and from persistent burglars and drug dealers.

I am fulfilling my responsibilities to the public, not adding to my own role in the sentencing process.Central to the government's criminal justice policy is the belief that 'prison works'.

I have consistently made clear my support for this.As the police have become more effective at targeting persistent offenders and the courts have sent more of them to prison, crime has fallen.

Over the last two-and-a-half years the prison population has risen by about 25%.

And, over the last two years, we have seen the largest fall in recorded crime since records were first kept in the middle of the last century.Prison takes criminals out of circulation, therefore preventing them from committing further offences while they are there.

Research has found that imprisoning a recidivist burglar may prevent between three and 13 burglaries for every year he spends in prison.

Prison also works because it sends a powerful message onto the streets.

In the words of the chief constable of Lancashire: 'There is no doubt that the fear of imprisonment is an extremely effective deterrent'.The police and the public have warmly welcomed my proposals.

I shall be publishing a white paper early next year as a basis for legislation.