Lawyers for convicted war criminal Omar Khadr are taking out a legal stick in an effort to speed his transfer to a Canadian prison.

They filed a notice of application Friday seeking to ask the Federal Court to review the federal government's failure to ask the U.S. to transfer Khadr to Canadian custody.

Lawyers for Omar Khadr, who is seen in this undated file photo, are trying to speed his transfer to Canada from Guantanamo Bay. Lawyers for Omar Khadr, who is seen in this undated file photo, are trying to speed his transfer to Canada from Guantanamo Bay. (Canadian Press)

Khadr has been serving an eight year sentence at the American military prison at Guantanamo Bay in Cuba since he pleaded guilty to war crimes in 2010.

But Khadr, 25, was eligible for transfer back to Canada last October and his lawyers say the government's delay in setting the wheels in motion is "unconscionable."

The Harper government has only said in the past that a decision would come in due course and has offered little explanation as to why it hasn't made a request.

The war crimes that Khadr was charged with include the killing of a U.S. army medic in Afghanistan in 2002.