Police Minister Judith Collins says she has "zero tolerance" for people who attack police officers but commenting on the Nikolas Delegat sentence could jeopardise a possible appeal.
Labour's Police spokesman Stuart Nash has called on Collins to direct the Crown to appeal the sentence and speak publicly about it given her strong comments about assaults on police in 2010.
Collins said she could not comment on the Delegat case because it was a judicial decision which was still within the period in which an appeal could be lodged.
"I'm not going to pre-empt that. That would be to interfere in the operation of the courts, it would be a breach of the Cabinet manual and could, in fact, completely stuff up any appeal rights that the Crown might have."
Nikolas James Posa Delegat, 19, was sentenced to 300 hours community work for the assault, 100 hours for assaulting a campus watch officer, 60 hours for wilful damage, and 60 hours for resisting arrest.
He has also been ordered to pay $5000 reparation to the police officer he punched, Constable Alana Kane.
It has raised questions about whether Delegat was let off lightly.
Collins conceded many people believed the justice system treated rich, white people with good lawyers differently to poor Maori.
"I think many people would say there is often shown in courts to be a difference in the way in which some people are seen to be dealt with. Whether that is because of what looks like an obvious situation, or it could be because of stuff we don't actually know about."
Collins had spoken about individual police assaults in the past and said she had "absolutely zero tolerance when it comes to people who attack police officers."
That was why the Government changed the law in 2010 to make attacking a police officer an aggravating factor in sentencing.
She said that was a pretty plain provision, and while Parliament could make the law it was up to the courts how they interpreted it.
Labour's Nash said the Government should tell the Crown Law Office to appeal the "ridiculously light" sentence handed down to Nikolas Delegat for assaulting a policewoman.
Nash said Prime Minister John Key said in 2010 the Government had a duty to send the message attacks on police officers were unacceptable but he had been silent on the Delegat case.
"An attack on a policewoman who was assaulted so badly she was on sick leave for two months warrants a jail term, not continued silence from the Government.
"The Prime Minister and the Police Minister must come out and condemn the sentence as totally inadequate and state that Crown Law will appeal. This would send a very clear message that this type of behaviour against police will not be tolerated by our communities and offenders will be punished accordingly."
He said Collins should be asking why Delegat was charged with assault instead of aggravated assault.
"The proper charge for punching a police officer is not plain assault, but aggravated assault, which includes attacking an officer in the line of duty and carries a maximum jail term of three years."
In 2010, Collins passed legislation that made assault of a police officer an aggravating factor in sentencing. She described attacks on police or Corrections officers as "an attack on the community and the rule of law".
Delegat, a student at the University of Otago, attacked and knocked Kane unconscious and assaulted a Campus Watch staff member during a drunken scuffle outside Starters Bar, in Frederick St, in March last year.
Delegat is the son of winemaker Jakov "Jim" Delegat and wife Kate.
A spokeswoman for Collins said she could not comment on judicial decisions.