Sydney – Tough border protection and asylum-seeker policies are critical to preserve multiculturalism, Australian Prime Minister Malcolm Turnbull said on Thursday, pointing to Britain's vote to exit the EU because of "anxiety over immigration".Turnbull, who is seeking re-election in national polls on Saturday, has been using the financial and political chaos created by the Brexit vote last week to argue for stable government and the return to office of his ruling conservative Liberal-National coalition.Canberra takes a hard line against asylum-seekers who reach Australia by boat, sending them to remote Pacific camps while others are sent back to their point of departure.The harsh policy has been slammed by human rights advocates and international institutions such as the United Nations."If you don't have strong border protection then people lose faith in the immigration system and the whole Australian multicultural project is threatened," the 61-year-old told The Australian newspaper."Australians have to know their government determines who comes to Australia, how long they can stay and the terms on which they can stay," Turnbull added, echoing Liberal predecessor John Howard's 2001 election line: "We will decide who comes to this country and the circumstances in which they come."Turnbull said there was a "very clear nexus" between border security and the success of multiculturalism and that in Britain "a large percent of people felt they had lost control of their borders".He cited the waves of asylum-seekers entering Europe and the bloc's border-free movement as trigger points."With freedom of movement in Europe the British government could not restrict the entry of people from other parts of Europe into the UK... And that has caused a lot of anxiety in Britain."Since the start of its "Operation Sovereign Borders" in September 2013, Canberra has managed to halt the flood of boat arrivals, and drownings, that characterised previous Labour administrations.Turnbull said at the coalition's election launch in Sydney last weekend that there have been no successful boat arrival in 700 days.