Wellington, Oct 21 (IANS): New Zealand witnessed a record net gain of 70,000 migrants in the year to September, the government statistics agency said on Friday, fuelling a row over the government's immigration policy.

The figure for the September year exceeded the previous annual record of 69,100 migrants in the year to the end of August, Xinhua news agency cited Statistics New Zealand agency as saying.

"The annual net gain reflects record high migrant arrivals and fewer migrant departures," population statistics manager Jo-Anne Skinner said in a statement.

"Most of the arrivals are people coming in with work visas, which also includes working holiday-makers."

Migrant arrivals numbered 125,600 in the September year, setting a new annual record, with 32 per cent arriving on work visas, 20 per cent on student visas and 13 per cent on residence visas.

Another 29 per cent were New Zealand and Australian citizens who can travel freely between the two countries.

Migrant departures were 55,700 in the same period -- almost 60 per cent of them New Zealand citizens.

Earlier this month, the government cut the overall number of residence approvals for the next two years from 90,000-100,000 down to 85,000-95,000, amid an ongoing debate over whether the country's infrastructure and public services were coping with the record arrivals.

Opposition lawmakers on Friday said the number of immigrants coming on work visas was helping to hold down wages and keep the country citizens out of jobs.

"Many work visas are issued to people working in low-skill, low-wage jobs such as farming, hospitality and administration. Yet we have 71,000 young people who are not in employment, education or training," said Iain Lees-Galloway, immigration spokesperson for the main opposition Labour Party.

"Our immigration policies should be focussed on bringing people with the skills we need to grow our economy and create opportunities for everyone," Lees-Galloway said in a statement.

"Changes to our work visa criteria are urgently needed to make the immigration system more sustainable, and able to deliver the skills New Zealand genuinely needs," he said.