Jon Boyle, Reuters -

PARIS (Reuters) - French Socialist presidential candidate Segolene Royal was embroiled in a new foreign policy row on Tuesday, denting her hopes of getting her gaffe-strewn campaign on track and catching up with rival Nicolas Sarkozy.
Canada issued a highly unusual public rebuke to Royal after she expressed sympathy with the idea of independence for Canada's French-speaking Quebec province -- at least the third foreign policy controversy to dog her bid for president.
Royal, attacked by critics as a political lightweight, has trailed Sarkozy since the interior minister accepted his centre-right party's nomination at a January 14 congress at which he courted voters drawn to Royal's more consensual image.
Royal told Canadian radio she and Andre Boisclair, visiting leader of the separatist Parti Quebecois, had common positions that included "the sovereignty and the freedom of Quebec."
Defending her remarks, Royal told Europe 1 radio she had not interfered in Canadian affairs: "What I said, which I confirm, is that as in any democracy, the people who vote are sovereign and free.
"So the people of Quebec will decide freely on their destiny when the time comes, if they are asked," she said.
Separatists there have been trying to break away from the rest of Canada for more than 40 years, causing headaches for the national government which responded swiftly to Royal.
"Experience tells us that it is highly inappropriate for a foreign leader to interfere in the democratic affairs of another country," Canadian Prime Minister Stephen Harper said.
Quebec was founded in the early 17th century by French explorers but passed into British hands in 1763 after the two nations fought a war in North America.
French President Charles de Gaulle sparked a diplomatic crisis when he declared "Vive le Quebec libre" (Long live free Quebec) during a visit in 1967. The remark prompted such an uproar that he cut short his visit and returned home.
Royal was involved in controversy last month during a Middle East tour when she was forced to correct comments in which she appeared to agree with a Hezbollah lawmaker who denounced the "insanity" of U.S. foreign policy.
During a trip to China this month, critics accused her of failing to push Beijing hard enough over its human rights record and criticised her for favorably comparing the Chinese justice system with that of France.
Royal is the head of a region in western France and has served as environment, family and schools minister in national governments. But she has little experience in foreign policy, which is the special preserve of French presidents.
Royal has also come under pressure over domestic issues.
There is widespread confusion over her tax plans and last week she was forced to suspend her spokesman after he accused her partner -- Socialist party chief Francois Hollande -- of being a political handicap for her campaign.