Woody Allen's latest European-inspired fairytale "Midnight in Paris" featuring French first lady Carla Bruni kicked off the Cannes festival Wednesday, drawing critics' cheers at an early preview.

Even before the light-hearted romantic comedy screened, the film generated major buzz when Bruni, who has a cameo, said she would not attend the premiere citing "personal reasons", stoking rampant rumours she is pregnant.

"Midnight in Paris" stars Owen Wilson as Gil, a successful Hollywood screenwriter on vacation in the French capital with his shrewish fiancee (Rachel McAdams) and dreams of the city as a haven for expatriate artists.

Spinning his wheels while working on his first novel, he takes a long walk at the witching hour and, when the bell tolls, Ernest Hemingway and F. Scott Fitzgerald arrive to pick him up in a 1920s Peugeot.

Gil's ensuing adventures lead him to the salon of Gertrude Stein (Kathy Bates) where he encounters Picasso, his enigmatic mistress Adriana (Oscar winner Marion Cotillard) and later, Salvador Dali (Adrien Brody).

Drawn into their lost world, Gil questions whether he can realise his artistic vision in the 21st century and begins to fall for Adriana.

Meanwhile his fiancee cheats on him with an insufferable know-it-all, played by the deliciously odious Michael Sheen, best known for his turn as Tony Blair in "The Queen".

Allen, who has had Europe serve as his muse in recent years with hits such as "Match Point" and "Vicky Cristina Barcelona", said he wanted to recreate the idealised vision of Paris born in the cinema.

"I learned about Paris the same way all Americans do -- through the movies," he told reporters.

"I didn't go to Paris until I was a grown-up, until 1965. When I went to Paris it was the Paris that I knew only from American movies. That's the same New York City that I've shown to people around the world in a picture like 'Manhattan'.

"It's the Manhattan that I don't see around me but recognise from movies and it was the same thing in Paris."

The red-carpet premiere of "Midnight in Paris" will officially open the 11-day event later Wednesday. It is screening out of competition.