A lawyer representing several Vancouver drug addicts is asking a judge for an injunction that would allow them access to prescription heroin.

Joseph Arvay says his clients and others were part of a clinical trial that provided them with pharmaceutical heroin.

They were granted special permission by Health Canada to continue to receive the prescription drug after they left the clinical trial, but the federal government then changed the rules to prevent the drug's distribution.

Arvay is asking the judge to essentially force Health Canada to abide by the former rules and allow access to the drug until their case goes to trial.

He says the federal government's "knee jerk" reaction is a violation of provincial jurisdiction over health care and of his clients' charter rights.

Without the prescriptions, Arvay says the addicts will be back on the streets of the Downtown Eastside shooting illegal drugs.