Citizenship and Immigration Canada is considering imposing new conditions on Canadians living outside the country who want to keep their Canadian passport, according to Foreign Affairs Minister Peter MacKay.

One option being studied involves taxing Canadian citizens living abroad, MacKay told a Senate committee.

Tens of thousands of immigrants are known to make short-term stays in Canada, only to leave once they qualify for and obtain citizenship.

Mackay's statement came in the wake of revelations that the operation to evacuate 15,000 Lebanese-Canadians from war-torn Lebanon this summer would cost taxpayers an estimated $80 million.