Hundreds of rallies hit the streets in cities and regional towns across Australia on Monday, with thousands of people adding their voices to a growing opposition to the government's hard line offshore processing regime. "Let them stay," they yelled, waving banners and posters protesting the imminent return of 276 asylum seekers to the country's detention center on the Pacific Island of Nauru.The 276, including 91 children (37 of whom were born in Australia), are to be sent back following a High Court decision last Wednesday that upheld the legality of the government's offshore processing regime - the morality of which is prompting loud and vocal challenges from unexpected sectors.The leaders of five of Australia's six states have broken ranks and offered to house the 267, doctors have spoken out about the level of child abuse on Nauru, churches have offered sanctuary, and the chief medical officer and surgeon general of the Australian Border Force, Dr. John Brayley, appeared before the Senate on Monday morning to tell the hearing detention is harmful to children."The scientific evidence is that detention affects the mental state of children, it's deleterious," he said. "Wherever possible, children should not be in detention." Late Monday, rally organizers, who said they have been overwhelmed by the level of support, called the offices of Prime Minister Malcolm Turnbull and Opposition Leader Bill Shorten and held up the phone as people chanted: "Let them stay."In Sydney's Town Hall Square, an estimated 4,000 people responded to the #letthemstay rallying cry and heard Sydney's Lord Mayor Clover Moore assert: "Our politicians have failed to deliver policies that address the global refugee crisis. They are lily-livered and gutless: more concerned with winning votes than saving lives." "I call upon our Federal Government to listen to the hundreds of thousands of people, including state Premiers and church leaders offering asylum, and take more responsible and compassionate action," Clover Moore added.In Melbourne, an equally large crowd shouted: "Malcolm, can you hear us? Let them stay."Refugee Action Collective's Chris Breen, who organized Thursday's rally in Melbourne following the High Court ruling, told Anadolu Agency that Prime Minister Malcolm Turnbull and Immigration Minister Peter Dutton are looking increasingly isolated. "It's beginning to feel like the tide is turning," Breen said."We had 5,000 people come out on the streets with just 24 hours' notice on Thursday and tonight we've got around 4,000. It's rare to rally that many people twice in less than a week." In Melbourne, a former asylum seeker who spent three years as a child on Nauru and is now an Australian citizen, told the cheering crowd he would keep telling his story until the government closes the detention centers.