Wellington, July 6 NZPA - People who attack police officers or prison guards are set to face tougher sentences after the Government decided to legislate to make assaults against them an aggravating factor.

Earlier this year Jason Palmer was the first prison guard to be killed in the line of duty. Latu Kepu, 21, is before the courts charged with Mr Palmer's manslaughter. Kepu allegedly punched American-born Mr Palmer, 33, on May 15 at Waikato's Spring Hill Prison.

Justice Minister Simon Power today said he got Cabinet approval on a proposal to amend the Sentencing Act.

"There has been a significant increase in the number and rate of assaults on law enforcement officers over the past five years and the Government has decided it wants to send a message that it is unacceptable," Mr Power said.

At present an offence against a law enforcement officer is not an aggravating factor that must be taken into account at sentencing.

"Though the new aggravating factor does not automatically require an increase in an offender's sentence, explicit legislation denouncing this type of offending will help ensure the courts impose appropriate penalties."

Between 2004 and 2009 assaults on police increased by a third, from 1869 to 2481, while serious assaults increased 38 percent, from 298 to 412.

The number of serious assaults on Corrections staff that required hospitalisation or time off work has been tracking down over the past year. However, between the 2004 and 2009 the total number of assaults increased from 151 to 304.

Police and Corrections Minister Judith Collins said the figures were a great concern.

"I'm confident that making assaults on police or corrections officers an aggravating factor at sentencing will help ensure that the courts impose heavy penalties for serious assaults on these people.

"Our police and corrections staff keep the community safe from our most dangerous people. This amendment sends a strong signal that the Government will do everything in its power to protect them while on the job."

Legislation will be introduced next month.

The Justice Ministry is also looking into how well existing special offences relating to assaults on law enforcement officers work and will report back to the Government by June next year.

Examples of current special offences include; a maximum of 14 years' jail sentence for using a firearm against any police, traffic, or prison officer; three years' imprisonment for the aggravated assault on a constable in the execution of their duty; provisions under the Summary Offences Act for assaults on a police officer with a maximum penalty of six months' imprisonment; and provisions under the Summary Offences Act for resisting a police, prison or traffic officer with a maximum penalty of three months' imprisonment.