Prime Minister Malcolm Turnbull has pounced on Labor's plan to increase the refugee intake to 27,000 a year, insisting it will strain the quality of resettlement services and the federal budget.
His warning came as Immigration Minister Peter Dutton toned down his rhetoric on resettling illiterate refugees following a backlash.
Labor maintains its plan is affordable but Mr Turnbull accused the opposition of pandering to the Greens for preference votes.
"There's no point bringing people in and forgetting about them, which is what a lot of other countries do," Mr Turnbull told reporters in Sydney.
The government believes the current level 13,750, due to rise to 18,750 by 2018/19, strikes the right balance.
The Greens are proposing an intake of 50,000, but have not done their homework on the costs and logistics, Mr Turnbull said.
"What Labor is proposing is too much. It will strain the system both in terms of giving good settlement services ... and the budget," he said.
"We are committed to a generous humanitarian program but we've got to do it properly."
Opposition Leader Bill Shorten stood by his criticism of Mr Dutton, as the prime minister accused him of demonising the minister.
"People in glass houses shouldn't throw stones, should they," Mr Shorten said.
Asked if he could guarantee the quality of resettlement services won't suffer, Mr Shorten told reporters on the NSW Central Coast the Parliamentary Budget Office had fully costed Labor's policy.
Mr Dutton came under fire on Wednesday for claiming "illiterate and innumerate" refugees would swamp welfare queues and take the jobs of locals if the annual humanitarian intake was substantially increased.
"I'm not going to stand back from what I said," Mr Dutton told 2GB Radio on Thursday.
But Mr Dutton toned down his earlier language, which critics slammed as xenophobic.
"Refugees contribute a lot, there are many success stories, we celebrate all of that but we need to be honest about the fact that many people come here with no English skills," he said.
