H.M. steps out as the Queen

It is what can only be called a majestic piece of acting. This was Dame Helen Mirren giving one of her most remarkable performances yet - as the Queen.

Filming scenes for a movie which chronicles the monarchy's crisis in September 1997 after the death of Princess Diana, her resemblance to Her Majesty was startling.

The 60-year-old star was joined by American actor James Cromwell, playing Prince Philip.

Using Cluny Castle near Aberdeen, the film-makers recreated the scenes outside Balmoral in 1997, where hundreds of bouquets and messages of sympathy were left by grief-stricken members of the public.

The film focuses on how, in the wake of the car crash which killed Diana and her lover Dodi Fayed in Paris, there was a growing clamour for the Queen - who was at Balmoral - to make some public acknowledgment of the tragedy.

Alex Jennings plays Prince Charles, Michael Sheen and Helen McCrory play Tony and Cherie Blair and Sylvia Syms appears as the Queen Mother.

As she signed autographs yesterday, Dame Helen - best known for her role as police chief Jane Tennison in Prime Suspect - impressed fans. 'I would never have picked her to play the Queen - she's too young,' said one.

'But, once made up, she looks really like her. It's uncanny.' The actress says she has long noticed her resemblance to the monarch. 'I look terribly like her,' she said. 'If I had to wear a dark wig for a role, I used to look like Princess Margaret.'

Talking about the emotion-filled reaction to Diana's death, she said: 'I'm not a monarchist, but I'm kind of with the Queen on this one. I'm not sure I get it, either. I wasn't in England at the time, so I was blissfully separated from it.'

The movie, called The Queen, is written by Peter Morgan. He also wrote The Deal, the TV film which told the story of the early pact between Tony Blair and Gordon Brown - in which Michael Sheen also played Blair. Being made by Granada, the movie will show the allegedly difficult relationship between the Premier and Her Majesty following Diana's death.

It will suggest Blair persuaded her to return to London and address the nation - although Dame Helen has insisted the Royal Family will be treated in 'an objective way'.

The movie will be released in cinemas next year before being shown on ITV. It is the second Queen Elizabeth that Dame Helen will play this year - she has just finished filming a Channel 4 drama about Elizabeth I.