The federal opposition has demanded the government release a national report into contamination linked to old fire fighting foam at military bases around Australia.
A preliminary report into toxic chemicals which leaked into ground and surface water near a dozen defence sites across the country is due to be released within the next week.
But four Labor MPs say the samples were taken as early as April and questioned why it has taken the government four months to make the report public.
A joint statement from Northern Territory senator Malarndirri McCarthy, Lingiari member Warren Snowdon, Solomon MP Luke Gosling and opposition defence spokeswoman Gai Brodtmann called on the coalition to stop dragging its feet on the issue.
They said affected residents in the NT, Victoria, Queensland and NSW have been left in the dark.
"We know the report is completed, so why not release it today?" they said.
"Communities have suffered stress and uncertainty over the Turnbull government's slow and uncoordinated response."
The Defence Department on Monday confirmed pollutants have been found near three Top End military bases, but says it's too early to know the effects on agriculture and health.
The federal government has already provided alternative drinking water to one Katherine landowner while it tested properties for pollutants from the nearby Tindal RAAF base, as well as the RAAF Base and Robertson Barracks in Darwin.
The Labor MPs said residents needed certainty about their future.
"The Turnbull government has learned nothing from its mismanagement of communication and consultation in Williamtown and Oakley."
A full nationwide investigation will begin early next year which will consider risks to human health and the environment.
The NT government on Friday urged people not to eat seafood from two Darwin creeks after contamination was detected in shellfish.
