Like Jo Mills, the character I played in Judge John Deed, I have a great sense of social justice and strongly believe in defending those who cannot defend themselves.

Feasting on the grotesquely enlarged livers of ducks and geese is morally indefensible. Foie gras is uniquely cruel in that it is one of the few 'foods' that is produced by intentionally inflicting illness on animals.

Birds raised for foie gras are force-fed up to two kilograms of grain and fat every day via a tube that is shoved down their throats. Force-feeding birds such a massive amount of mush - the equivalent of forcing you or me to eat roughly 20 kilograms of pasta per day - causes their livers to swell to as much as 10 times their normal size, resulting in a disease known as hepatic steatosis.

The pipes sometimes puncture the birds' throats and many suffer from ruptured internal organs, fungal and bacterial infections and liver failure. Heartbreaking undercover video shows birds trembling in fear as the people with the force-feeding pipes approach. Some are too sick or depressed to stand up. Many don't survive the ordeal - an average of 20% of ducks on foie gras farms die before slaughter.

It's no surprise that force-feeding birds has been denounced by every expert in the field of poultry welfare. Dr Christine Nicol, a tenured poultry husbandry professor at the University of Bristol, believes that foie gras production causes unacceptable suffering. She says: "It causes pain during and as a consequence of the force feeding, feelings of malaise as the body struggles to cope with extreme nutrient imbalance, and distress due to the forceful handling."

In fact, the scientific consensus against foie gras is so strong that its production has been banned in more than a dozen countries, including the UK. The British Academy of Film and Television Arts (BAFTA), the Brit Awards, Wimbledon, Lord's Cricket Ground and the Royal Shakespeare Company have all recently pledged not to serve or sell foie gras, and Prince Charles refuses to allow it on royal menus.

Almost every major store in the UK, including Selfridges and Harvey Nichols, has dropped foie gras because it's so cruel. But there are still holdouts.

Even though People for the Ethical Treatment of Animals (Peta) has given Fortnum & Mason a wealth of scientific and expert evidence to show how inhumane foie gras production is, the retailer continues to peddle this 'torture in a tin'.

Last summer, I teamed up with two of my West End stage-mates, Peter Egan and Carley Stenson, for a Peta protest outside the Piccadilly retailer. Banding together behind a banner that resembled a stage curtain and read, 'Fortnum & Mason: Bring the Final Curtain Down on Foie Gras', we urged consumers to steer clear of the department store until it agrees to remove foie gras from its shelves and menus permanently. I'm very proud to be among a growing list of British celebrities - including Twiggy, Joanna Lumley, Sir Roger Moore, Bill Oddie, Ricky Gervais, Dame Vera Lynn and others - demanding that Fortnum & Mason stop profiting from the abuse of innocent animals. I now urge all of you "women of substance" reading this to join in the effort to stop the production and sale of foie gras by visiting PETA.org.uk for more details on the campaign and information on what you can do to help!