Ken Clarke can already refuse victims compensation for violent crimes if they are of bad character. Now he wants to ban anyone with an unspent conviction from applying

Ken Clarke is announcing major reforms to the Criminal Injuries Compensation Authority later today. The scheme, which was set up in 1964, makes payments - according to set tariff figures - for those who are physically injured by a violent criminal act.

The government estimates that the scheme has awarded 20,000 people with criminal records a total of more than ?75m over the past decade. In one case, a convicted rapist was awarded ?62,000 for serious injuries, including the loss of a leg.

Under the proposals, those with unspent convictions will be banned from applying for compensation under the scheme.

It sounds an attractive reform. But on a human level, there is danger. There is nothing which directly links the prohibition on compensation to the nature of the applicant's previous conviction. For example, a mugger could not get compensation if he himself were later mugged. Or imagine a 20-year old student who is caught returning from Amsterdam with

cannabis in her rucksack. She gets a fine, or perhaps a community service order. Four years later, she has a good job and is walking down the street when she is violently assaulted. Under Clarke's proposals, she will not be entitled to compensation under the scheme, because fines and community service do not become 'spent' until after five years.

Leaked reports suggest that there will be exemptions to this rule, such as prisoners injured while rushing to the aid of a prison officer under attack, or people convicted of a minor offence such as shoplifting. The injustice arises just over the 'minor offence' threshold.

Of course, it could be argued that the woman can sue her attacker. But why should she have to subject herself to the aggravation ? and physical and financial risks ? associated with that? And what if the attacker doesn't have the money to pay? The Criminal Injuries Compensation Scheme was set up to avoid precisely this type of problem.

Will this reform also result in a willingness by police and prison officers to use increased physical force when restraining or questioning known criminals? If a police officer knows Cica would not entertain any claim of assault, because the individual has a criminal record, it makes it less likely that they will face scrutiny over their actions. Again, it is no answer to say that they can bring a civil action ? the absence of legal aid makes this a very difficult claim to launch.

What Clarke does not mention is that the current version of the Criminal Injuries Compensation Scheme already contains something not too dissimilar to his rather arbitrary proposal. Under paragraph 14(3) of the scheme, Cica must refuse or reduce an award because the applicant's character ? as demonstrated by his/her unspent convictions ? makes it inappropriate to make a full award. So the scheme currently has discretion to refuse awards to serious criminals. And it is widely known that the Cica will reduce or refuse an award if the applicant is himself at fault ? whether he has a previous conviction or not. Ken Clarke's proposal appears to make it mandatory to refuse awards, which is a step too far.

This article was amended at 3.40pm on January 30 2012 to correct the paragraph reference to the Criminal Injuries Compensation Scheme and to make it clear that Cica must (rather than can) refuse an award if it finds evidence of bad character