The last remaining rough sleepers at the Flinders Street Station camp have been urged to accept a "pathway" out of homelessness or face eviction.
Protesters who have moved into the site have also been warned to move on.
Housing Minister Martin Foley confirmed on Tuesday that 15 people from the camp had been "successfully housed" while four others were placed in drug and alcohol residential rehabilitation facilities.
"This camp will have to break up today. That site later today will be a building site," he said.
A group of people sleeping rough at Flinders Street Station were digging in despite being told that they will have to move on by midday on Wednesday to make way for Melbourne Metro construction work.
About a dozen people remain camped along Flinders Street joined by a small contingent of protesters wielding placards.
"Some of them are saying they will stay but when push comes to shove I don't know," said Lisa Peterson, a supporter of the group.
"Some are saying they won't."
Ms Peterson said she was concerned that promised accommodation had not been forthcoming and that goodwill towards the homeless have dried up in recent weeks. A media contingent is at the scene, mostly watching the camp from afar.
Mr Foley said some homeless people were reluctant to accept offers of accommodation and support from housing agencies.
"The culture of rough sleeping and homelessness in some people is a deeply embedded one. If you've been homeless and on the streets for some time, that's your life," he said.
Last week the state government announced it would deliver a $9.8 million emergency response package to fund immediate housing for the city's street homeless.
Jonathan "Link" Hardy said he had been sleeping at Flinders Streets Station since last month and has been homeless since mid-2013.
Mr Hardy is deaf and communicated, haltingly, using a notepad and pen. The aspiring body builder explained that he was trying to get accommodation by applying for private rentals.
"I not do drugs, I do not smoke and I lift and train everyday," he said. "I want a house, I wait for a house."
He said he might move from Flinders Street if asked by police but "maybe [when] everyone leave, I come back ... I'm not sure."