The Prime Minister also has stronger support among those aged from 40 to 55 on this question, trusted by 51 per cent against 30 per cent for Mr Shorten. While the Coalition has often held an advantage over Labor in polls on border security, the new results show the political risks for Mr Shorten even at a time when he has narrowed the gap against Mr Morrison as preferred prime minister. The Opposition Leader has come under weeks of attack from the government after supporting a crossbench bill to fast-track medical transfers from Nauru and Manus Island, as some asylum seekers wait more than five years in detention. Mr Shorten told his party’s national conference this week that a Labor government would turn back asylum seeker boats when safe to do so, maintain offshore processing, continue character checks on migrants and deter people smugglers. "We cannot, we must not and we will not permit the re-opening of their trade in human desperation and the drownings and the irreplaceable loss of life that it brings," he said.

Pledging a "strong, compassionate and sustainable" approach to border control, he promised an increase in the humanitarian intake from 18,750 under the Coalition this year to 27,000 under Labor by 2025 with a further 5000 places to be sponsored by community organisations over time. Loading The power of border protection to sway an election is a source of regular dispute between Labor and Coalition supporters but an independent survey conducted in July and August found a significant decline in concern about asylum seekers. Asked without prompting to name the most important problems facing Australia, only 1.3 per cent said "too many boat people" or made similar remarks in the 2018 survey by the Scanlon Foundation at Monash University, down from 10 per cent in 2013. The proportion of voters who named the poor treatment of refugees was also 1.3 per cent this year, down from 3 per cent in 2013, when the federal election was held after years of higher boat arrivals during the Rudd and Gillard governments.

This part of the Scanlon report was based on a telephone survey of 1500 people and found voters were split on the treatment of asylum seekers. Asked if they were concerned the treatment was too harsh, 24.9 per cent said "a great deal" and 23.9 per cent said "somewhat" but another 18.8 per cent said they were "only slightly" concerned and 29.7 per cent were "not at all" concerned about the issue. Immigration Minister David Coleman has stepped up warnings that Labor would dismantle offshore processing by supporting the medical treatment bill, which constrains the discretion of the minister to reject transfers to Australia. "We’ve been very successful, it’s hard to dispute that – we’ve had no successful boat arrivals for four years, we’ve stopped deaths at sea," Mr Coleman said. Labor rejects the claim it would dismantle offshore processing and insists the medical transfer bill does not weaken the rules because the minister can refuse any transfer if he or she is concerned about security, as defined in the Australian Security and Intelligence Organisation Act. Labor defence spokesman Richard Marles this week argued the bill gave "absolute primacy" to the minister when deciding transfers even when this was not a security matter, over-riding the medical panel that advises on these questions.

"The minister should have the final say," Mr Marles told Sky News. "That has been our position and it is really important that that be the case." Mr Coleman pointed to specific wording in the bill that restricts the minister’s discretion, given the definition of security in the ASIO Act is the only grounds for rejecting the medical panel’s advice and it emphasises border integrity and does not include a character test to cover past criminal or violent behaviour. Decisions on medical transfers are made with unfettered ministerial discretion under current law. The Ipsos survey of 1200 respondents was conducted by telephone from Wednesday to Saturday, before the Labor national conference, and has a margin of error of 2.9 per cent.