An American professor scheduled to teach at Carleton University this fall was denied a work permit because of his arrest during a protest 26 years ago — a move he says has chilling implications for activists and protesters on both sides of the border.

"I've not been convicted of a crime," said Tom Juravich, who teaches labour studies at the University of Massachusetts in Amherst. "But somehow now, simply because I was arrested 26 years ago, I seem to be a potential threat here in Canada."

He said that when he tried to cross the border at Cornwall, Ont., last week, Canadian border agents told him his file showed he was arrested by U.S. authorities in 1981. That was during a protest on a union picket line, Juravich said.

He added that he was told he must provide further documentation about the arrest in order to be cleared for a work permit.

Juravich said he visited Canada more than 50 times in the past two years to work and to spend time with his partner, Teresa Healy, who lives in Ottawa.

The situation implies that young activists and protesters may have trouble crossing the border in the future, he said, and that may discourage some people from engaging in activism or participating in protests.

"I think this is going to have a chilling impact on the kind of legitimate dissent that we consider as a part and parcel of the democratic process," he said.

He blamed his recent problem on the way information is now shared between Canada and the United States, as a result of terrorism fears.

Canadian border agents can't be expected to interpret decades old legal documents from another country, he added.

Patrizia Giolti, spokeswoman for the Canadian Border Services Agency, said in an e-mail that the agency cannot comment on Juravich's specific case.

But she said information sharing between the two countries is nothing new and that people may be deemed inadmissible because of criminal charges laid in another country, even if those charges are later withdrawn.

"To allow an officer to determine their admissibility, they must provide  complete details of the charges, convictions, court dispositions, pardons, photocopies of applicable sections of foreign law and court proceedings," she added.

Meanwhile, Juravich's situation is also causing problems for Carleton University, where Juravich was hired to teach one course in labour culture and another in sociology.

"To lose two classes taught by a sort of internationally reputable scholar is a disaster," said Rianne Mahon, director of the university's Institute of Political Economy, which hired Juravich.

She said the news that Juravich was denied a work permit came as a shock.