At least 250 men are holed up in a church in central Brussels on hunger strike with more than 200 at other locations in the Belgian capital.
They demanding immediate recognition as residents in Belgium and want to be collectively granted settled status and say they have not eaten since May 23.
Ahmed, who is one of the leaders of the strike told Euronews: "I sometimes wonder how our government can sleep when it has so many people starving, dying and suffering.
"They are in a state of agony and it continues to sleep peacefully."
The men mainly come from Tunisia, Morocco, Algeria, Egypt and Pakistan and say they have been living and working under the radar in Belgium for years and in many cases decades.
Without official papers, they are unable to access proper healthcare, financial services or any other benefits granted to Belgian residents.
The volunteer medical support insists the situation is critical.
Cecile Vanheuverzwijn is a doctor who has set up a makeshift aid station in the Beguinage church and told Euronews: "the patients are getting worse and worse. We've seen several heart problems, renal problems, psychological difficulties and several suicide attempts."
The hunger strike is only getting limited attention in Belgian press - but with the health situation deteriorating, pressure is mounting on the government to act.
It's thought there are 150 thousand undocumented migrants in the country.
The Belgian federal immigration minister, Sammy Mahdi insists he won't be blackmailed into making a collective concession to approve the asylum requests for groups of people.
"It is frustrating. We are trying to help people as much as possible to get their dossiers being treated as fast as possible. But of course, not every undocumented person, not every person who is here can stay in Belgium. And so we are trying to give them the right information, but the hunger strike is not going to help" he told Euronews.
The men refuse to go through the application process individually for fear they will be deported.
The Belgian government believes the protest is an example of why the EU needs better coordination in supporting asylum seekers to be relocated across the bloc.