Pop star Lily Allen is convinced her theatre writing debut on a musical adaptation of Bridget Jones's Diary may never make it to the stage.

The Smile singer wrote the music and lyrics for the stage show based on the novel by Helen Fielding, and the production had been expected to open in London's West End in 2011.

However, the project has been marred by delays and setbacks, and was thrown into turmoil in 2012 by the exit of lead actress Sheridan Smith, who had reportedly been tapped to take over the title role made famous by Renee Zellweger in the movie series.

Allen has now admitted her hard work may go to waste as the musical may never be seen by the public.

She tells Popjustice.com, "It's finished and it's brilliant. But I don't know if it will ever see the light of day."

When pressed on the details, Allen adds, "I cannot divulge", before revealing her favourite song from the show: "It's called Yummy and it's Bridget singing to a fridge."