The Abbott government will never move away from its policy of turning back asylum seeker boats, the immigration minister, Scott Morrison, says.

Speaking at a NSW Liberal party function on Saturday, Morrison praised the Coalition for not flinching in the face of critics who said they could never stop the boats.

“But there seems to be some view that because we’ve only had one boat this year, that somehow we can relax, we can walk away from those policies and that we can give it away,” he told the Penrith crowd, in Sydney’s west.

“Those who oppose those policies would like nothing more than for us to let down our guard again.

“It won’t happen. The government will never, ever move away from the policies that we know work.”

Morrison claimed that the level of concern within the Australian community about immigration numbers was at its lowest since the 1970s.