Magistrates are facing calls to crack down on offenders who assault police officers, after figures revealed a massive rise in the number of attacks on Surrey's constables.

Surrey Police Federation raised concerns last week after discovering that only a tiny proportion of offenders were serving jail sentences for the crimes, which had risen by a staggering 141 per cent in the last year.

This coincided with the launch of a county-wide initiative to combat town centre disorder.

In Walton the figures more than doubled, with 10 assaults on officers recorded during April and May, compared with four in the same period last year. And it is a similar picture in Surrey as a whole, where 41 officers were assaulted in the same period this year, compared with 17 last year.

More worrying, said the Federation, is that of 166 convictions for the offence between September 2003 and February 2004, only 19 resulted in a prison sentence.

Surrey's Assistant Chief Constable Mark Rowley described violence towards police officers as an attack on the justice system itself.

But data revealed that jail terms for the offences ranged from two weeks to five months. The most common form of punishment were fines, which averaged just £100.

John Miskelly, chairman of Surrey Police Federation, which represents the front line officers, said the situation was pitiful.

Surrey Police have increased their presence in town centres in the last year following the introduction of Surrey Street Standards, aimed at cracking down on antisocial behaviour and disorder in places such as Walton.

It includes the red and yellow card scheme, under which troublemakers are given warnings for rowdy behaviour. But the Surrey Police Federation said this has made officers more vulnerable.

Assistant Chief Constable Rowley backed the Federation's concerns, saying violence towards officers had a detrimental effect upon society.

"We are very disappointed that the criminal justice system does not appear to be supporting our officers in their determination to intervene to reverse the trend in violence and antisocial behaviour," he said.

"The officers doing this difficult work on behalf of the public deserve the complete support of the criminal justice system. It is a disgrace that they do not always receive it."

The Surrey Police Authority has asked the Magistrates' Court Committee to ensure clerks who advise magistrates on the law were aware of the seriousness of the offence.

John Baker, a senior legal advisor to the county's magistrates, said assaults ranged from minor incidents to more serious attacks that resulted in injury.

But he added: "I will be reminding magistrates who have no legal training that when considering sentences for these kind of offences their starting point must be custody. Where they don't do it they have to give reasons why."

A Surrey Police Authority report on sentences handed to people convicted of assaulting officers is to be published in November.

ksaines@london.newsquest.co.uk