Director Simon Curtis on the making of A Short Stay in Switzerland.

I joined the project when it was at a fairly advanced stage - producer Liz Trubridge had been working on the script for a couple of years with the dramatist Frank McGuinness.

My first task was to get to know the family who inspired the drama and to acquaint myself with the footage BBC journalist Fergus Walsh had shot for Panaroma telling the story of Anne Turner, the doctor who ended her life at a Swiss clinic. There is no doubt this material - which everyone joining the production saw - helped give our film great emotional depth.

We had a four-day rehearsal period, one of the highlights of which was meeting a doctor who gave us a harrowing insight into the plight of patients diagnosed with PSP (Progressive Supranuclear Palsy) - the disease that strikes Anne. Another was when the three Turner children came in to meet the actors playing them. On the day of Anne's death, they had broken into song as a way of supporting her and I will never forget them singing fearlessly in rehearsal room, teaching their counterparts what they had done.

We had a 22-day shoot for the 90-minute film and it would have been impossible without the great skill of two trusted colleagues from last year's Cranford: Phil Booth, a first assistant director who is a genius at working out a schedule, and Ben Smithard, who immediately felt we should shoot this on a Genesis HD camera. He managed to secure a deal enabling us to have two cameras and this decision helped us to complete our schedule each day. It also helped the actors to shoot the emotional scenes in a minimum of takes.

In one five-minute dialogue between Julie Walters and Harriet Walter, who plays Anne Turner's best friend, Claire, we were able to cross-shoot the entire scene in a single take.

We also decided to dispense with the dolly and shoot handheld using as few lights as possible. On one interior scene without lights we ground to a halt when a freak near eclipse over West London left us sitting in darkness.

The undisputed star of our shoot was Julie, who raised the game for us all on both sides of the camera. Every day demanded stunts and hugely emotional material and she boldly took on everything that we threw at her.

Most of the film was shot in Hampton, including a tiny bungalow where we shot for eight consecutive days. Our final sequence was to be shot in Zurich and the only way to make it work was to shoot our last morning in London, fly to Switzerland and start shooting on arrival at Zurich airport. Believe me, it was a very “short stay in Switzerland”.

A Short Stay in Switzerland
Production: BBC Productions
Director: Simon Curtis
Producer: Liz Trubridge
Writer: Frank McGuinness
Distributor: Digital Rights Group
Broadcast: Sunday 25 January at 9pm on BBC1
Project summary: A one-off drama, inspired by the true story of Anne Turner, who travelled to Switzerland in 2006 to take her own life.

Simon Curtis: My tricks of the trade
Phil Booth - the first assistant director is the unsung hero of a drama shoot. Phil is masterful at anticipating tomorrow's problem and ensuring we avoid it.
Running gags - I love the banter with cast and crew on set. Humour has a way of bringing us together.
Reinforced director's chair - I go through at least one on a shoot and, true to form, was ridiculed after collapsing on the floor just as a huge emotional take was starting.