Image copyright PA Image caption Oscar Isaac, who plays Poe Dameron in Star Wars: The Force Awakens, made a surprise appearance

Sir Alec Guinness branded co-star Harrison Ford a "languid young man" in a letter read by Star Wars actor Oscar Isaac at a performance in London.

Writing during filming of the 1977 film Star Wars: A New Hope, Sir Alec said: "Can't say I'm enjoying the film."

The letter from the late actor, who played Obi Wan Kenobi, talks about the film's "rubbish dialogue".

Isaac, who plays Poe Dameron in Star Wars: The Force Awakens, was at Letters Live at Freemasons' Hall in London.

Sir Alec wrote to his friend Anne Kauffman: "New rubbish dialogue reaches me every other day on wadges of pink paper, and none of it makes my character clear or even bearable."

He said he was working with "Mark Hamill and Tennyson (that can't be right) Ford. Ellison? No! Well a rangy, languid man who is probably intelligent and amusing."

Letters Live sees actors and performers reading out literary correspondence to a live audience, aiming to celebrate its enduring power throughout history.

Each show benefits a range of literary charities.

Image copyright PA Image caption In his 1977 letter, Sir Alec calls co-star Harrison Ford "probably intelligent and amusing"

Sherlock actors Benedict Cumberbatch and Louise Brealey also took part, along with Cumberbatch's wife, theatre and opera director Sophie Hunter.

Cumberbatch read out a letter by American author Mark Twain to the American poet Walt Whitman, which paid tribute to all the changes he had witnessed in the world over the course of his lifetime.

Image copyright PA Image caption Actor Benedict Cumberbatch performed at Letters Live

Cumberbatch and Brealey then performed letters between Bessie Moore and Chris Barker, two sweethearts separated by World War Two.

The pair enacted the love story last year, in BBC Radio 4's adaptation, My Dear Bessie.

Hunter read out a letter from deaf and blind woman Helen Keller to the New York Symphony Orchestra, thanking them for the music which she had experienced through the radio by feeling the vibrations.

The last run of Letters Live events saw letters written by names including David Bowie, Marge Simpson, Elvis Presley, Janis Joplin, Charlotte Bronte, Jane Austen and Che Guevara being read out by a host of stars.