Nicole Kidman defends performance as Princess Grace of Monaco

Oscar winner Nicole Kidman defended her new picture Grace of Monaco after a critics' mauling at the opening of the Cannes Film Festival - but admitted a boycott by the late princess' family was "awkward".

Kidman, 46, stars as Grace Kelly, the American actress turned European royalty, in the French production which kicked off the 12-day extravaganza, having generated serious off-screen drama ahead of its red-carpet premiere on Wednesday.

Critics were scathing after an early preview, with Britain's The Guardian calling the picture a "breathtaking catastrophe" and "so ... wooden that it is basically a fire risk", while industry magazine Hollywood Reporter savaged a "stiff royal soap opera that drags where it should dazzle".

Kidman, who at least bears a remarkable physical similarity to the statuesque Grace in the film, gave her maligned director Olivier Dahan a little squeeze as she faced the press with a smile.

When asked about the decision by Grace's children, Prince Albert and his sisters Caroline and Stephanie, to angrily dismiss the film this month as "totally fictional", she said she hoped they would still watch it one day.

"Obviously I feel sad because I think that the film has no malice towards the family or in particular towards Grace or [Prince] Rainier," she said.