Police figures show the number of constables on the beat has dropped by nearly 18 percent across the country in the last six years.
Labour Party's police spokesperson Kelvin Davis, who obtained the data under the Official Information Act, said it was "a terrible indictment on the Government", which cut police funding by $15.3 million in the Budget.
Mr Davis said this came on top of flatlining funding in real terms since 2009.
He said at the same time, revenue gathering for traffic infringements was up by nearly $15 million this year, which went into the Government's coffers.
Currently, there are 2593 'general duties' constables deployed nationally, 569 fewer than in 2009.
The biggest fall was in Wellington, where the number of general front-line officers dropped by just over 32 percent.
Of the country's 12 police districts, only Counties Manukau escaped cuts.
However, Police Minister Michael Woodhouse said Mr Davis was "either being tricky or is utterly confused".
"Either way, his comments are untrue. The simple fact is that both frontline and overall police numbers have increased under the National-led Government, and our communities are safer as a result."
Mr Woodhouse said this year's budget included more than $1.5 billion "to support and invest in our police - the most ever."
The Police Association was sceptical, however.
Its president Greg O'Connor said there was no doubt that police funding had fallen in real terms.
Mr O'Connor said Government funding cuts meant police were struggling to keep up the level of service, which the public expected.
Under the police's crime prevention strategy, more staff were working in specialist areas to stop crime happening in the first place.
However, he said this meant fewer staff rostered on around the clock to deal with crime that had happened.
"The area under the most pressure is the response area - responding to calls from the public - and that's where cuts in the Budget have impacted.
"You can't fault the importance of crime prevention, but there are always going to be times when the public do need police and they need them now.
"And that's the area, the general duties area, where the numbers are under the most pressure."