Kevin Morton told the Police Association of NSW conference on Tuesday that the cost of training was prohibitive.

NSW is the only state where aspiring cops have to spend thousands of dollars and months of their lives to join the force, he told the conference that was attended by the police minister and commissioner.

He says it's putting off people who have other responsibilities or not enough money.

Prospective cops stump up about $17,000 during their recruitment and training.

"We're missing out on quality potential police officers in this state because people simply can't afford the application process," Mr Morton said.

Aspiring recruits first have to complete a university certificate course in workforce essentials before they can even apply to join the force.

Successful applicants then have to spend more money during the almost nine-month training course at Goulburn Police Academy, where they can be restricted to the training facility and separated from their families.

"They're not even getting paid for it - in fact, they're paying out of their life savings to do it," Mr Morton says.

The state has cancelled the next scheduled training course for new officers in June because not enough people applied, and is staring down the barrel of a shortage of officers, he says.

Police Minister Paul Toole rejected the claim cost was putting people off joining the force.

"We've already got six classes that have been running down at the academy for new officers coming through," he said.

The NSW government promised an additional 1500 police officers over four years in 2018 and 950 had already joined the force, he said.

Attracting new recruits was not the only issue, retaining officers was also an issue.

"We want to look at ways we can support police officers, not when they start up their career, but when they continue in their career as well," Mr Toole said.

Other factors could be putting people off joining the force, aside from training costs, he said.

"We are finding that the recruitment of new officers has become more challenging over the last two years," he said, pointing to COVID as one cause.

"But I do make the point we are going to continue to ensure that this is an attractive profession."

Premier Dominic Perrottet said recruitment issues were not limited to police and there was a labour shortage across the country.

Unions representing police, teachers, nurses and other staff have been seeking pay increases above the 2.5 per cent cap on public sector wages.

Mr Perrottet has hinted there will be some relief for them in next month's budget.

Opposition Leader Chris Minns said the high cost of living in Sydney was an impediment to attracting police.

"It's just unconscionable to be in a situation where we're asking young police officers to police a city that for many of them, they simply can't afford to live in and raise a family," he said.

The starting salary for a probationary constable in NSW is about $76,000 plus allowances.

Salaries increase by about $3000 annually for the first four years before officers progress to senior constable in their fifth year on the job, earning $86,517.

Australian Associated Press