Robin Long says he has been trying to gain refugee status in Canada because he believes he would suffer harm if he were to be sent back to the U.S. (CBC)

An American war deserter living in Canada since 2005 has lost his bid to stay in the country while his legal case unfolds and could be deported as early as Tuesday.

A Federal Court judge in Vancouver on Monday rejected Robin Long's application for a stay of his deportation order.

The 25-year-old fled to Canada to avoid serving in Iraq. He was arrested in Nelson, B.C., last October on a Canada-wide warrant.

Long had said he tried to gain refugee status in Canada because he believes he would suffer harm if he had to return to his home country.

In her ruling, Federal Court of Canada Justice Anne Mactavish said Long did not provide clear and convincing evidence that he would suffer irreparable harm if he is returned home.

Outside the court, one of Long's supporters said he is unaware of any other recourse for Long and that he will likely be deported on Tuesday.

Long settled in Marathon, Ont., with his partner and their small child when he came to Canada three years ago.

He then decided to go to B.C. to work. When the Canada Border Services Agency didn't get a response in Ontario for an interview, a warrant for his arrest was issued.

Citizenship and Immigration Canada was willing to offer Long a pre-removal risk assessment in Ontario, but he left the province leaving no forwarding address.

The assessment evaluates the risk a refugee claimant will face if he or she is to be sent back to the originating country.

With files from the Canadian Press