Former British royal Sarah Ferguson was so moved by Dame Helen Mirren's performance in The Queen she broke down in tears.

The Duchess Of York admits she found the Oscar winner's onscreen portrayal of British monarch Elizabeth II totally convincing, dubbing her former mother-in-law "an amazing woman".

She says, "When I saw the film I thought, 'I would never betray this woman.' She's so amazing, as a leader and as a woman."

Ferguson confesses daughters Beatrice and Eugene were delighted by the film's Oscar success.

She adds, "They jumped up and down and said, 'Yes - granny!'"