Anti-immigration politician Pauline Hanson on Wednesday warned Australia was in danger of being swamped by Muslims and told those unwilling to give the nation their undivided loyalty to "go back where you came from." Twenty years after saying Australia was at risk of being overrun by Asians, Hanson used her first speech to parliament since being re-elected in July to declare: "I'm back." "Now we are in danger of being swamped by Muslims who bear a culture and ideology that is incompatible with our own," she told the Senate in Canberra. Pauline Hanson's One Nation party won four seats in the Senate on strong backing for her long list of anti-Muslim policies in the July polls, marking a stunning comeback for a woman whose populist views caused a stir in Asia during her first divisive political stint in the late 1990s. She said on Wednesday that while Australia had embraced migrants from all over the world, many of whom had integrated into society, Islam had had an impact on Australia like no other religion. "Islam can not have a significant presence in Australia if we are to live in an open, secular and cohesive society," said Hanson, who famously ditched her fish and chip shop to represent Queensland ahead of her first foray into national parliament. Warning that if changes were not made now, "there will be no hope in the future," she called for an end to Muslim immigration and a ban on the burqa. "In addition, no more mosques or schools should be built and those that already exist should be monitored in regard to what they are teaching until the present crisis is over." As she spoke, Greens leader Richard Di Natale walked out with his party colleagues. "Racism has no place in Parliament but that is what we have just heard from Senator Hanson. I stand with those people hurt by her words," he tweeted. Hanson left parliament when she lost her seat in 1998 and quit as One Nation's leader in 2002. But she returned to lead the party in 2014 after a 12-year hiatus, a period during which she was jailed for several months for electoral fraud before her sentence was quashed. Her decision to return paid off in July, as voters disillusioned with the ruling conservatives and opposition Labor voted her and three others from her party into the Senate. "If you are not prepared to become Australian and give this country your undivided loyalty, obey our laws, respect our culture and way of life then I suggest you go back where you came from," she said on Wednesday. "If it would be any help I would take you to the airport and wave you goodbye with sincere best wishes."