We all felt it was time to look at a woman in comedy and it would be interesting to portray a comic whose life was more colourful off screen than her roles ever suggested.

Deeper research into her story suggested that we were dealing with a bittersweet tale - humorous moments, but tinged with sadness - and the project became a joint effort, with the support of Ben Stephenson and Anne Mensah in BBC Drama.

We were keen to avoid a cradle-to-grave treatment and instead find one episode in her life that captured her core dilemmas - her work, her personal life, loyalty and adventure.

Writer Stephen Russell grasped this brilliantly and forged a revealing, satisfying narrative around the love triangle with her husband, John Le Mesurier, and her driver, John Schofield, covering just a few years.

We resigned ourselves to the fact that Matron - Hattie's iconic Carry On role - wouldn't feature, but we were determined the story should work for any viewer, even if they'd never heard of Hattie Jacques.

In fact, the filming of Carry On Cabby coincided with our story. This was an unusual lead role for Hattie and her favourite in the series.

With themes of sexy cab drivers, unfulfilled marriages and female empowerment, Cabby provided plenty of parallels with Hattie's personal narrative.

From talking to some of Hattie's friends and family, we were struck by the very civilised way in which the marriage break-up was handled and the conviction that, although Hattie's affair with Schofield ended badly, she would make the same gamble again.

We didn't want to create goodies and baddies in this story - there is always more to the end of a relationship than one person's actions - and this was the perfect story to explore that theme.

Director Dan Zeff made sure that moments of great strength and human weakness were revealed in each of the characters.

One of the most poignant aspects of the script is the irony that Hattie and her husband rediscover each other through the process of separating - and seem to fall in love again just as they are divorced.

Casting started with a shortlist of one for the main role. Luckily Ruth Jones was a fan of Hattie and, soon after reading an early draft of the script, she was on board.

John Schofield was the opposite - raw, intuitive, passionate and bristling with physical presence. Robert Bathurst and Aidan Turner fulfilled these criteria perfectly and make a fantastic combination.

With three weeks to shoot a 90-minute film, the schedule was tough - not least for Ruth, who appears in nearly every scene with detailed hair and make-up each morning.

To her great credit she threw herself into it, delivered a ravishing performance and, through her unflagging good cheer, helped make the frantic shoot a pleasure.

Seb Barwell jointly produced Hattie with Richard Osborne.

Hattie is on Wednesday, 19 January at 9pm on BBC Four and BBC HD.

Comments made by writers on the BBC TV blog are their own opinions and not necessarily those of the BBC.