Cherished is based on the true story of Angela Cannings, who was tried for the murder of her babies. She spent two years in prison battling for justice before her conviction was eventually quashed.

Angela was convicted of the murder of two of her children with no physical evidence. Her acquittal created a landmark in legal history, resulting in a change of the law. Since then, nobody can be convicted in a criminal case on expert witness alone without proper physical evidence, such as that which would be required in any murder case.

Following the impact of the Cannings' judgment, a review into other possible miscarriages of justice has revealed that up to two dozen women might have been wrongly convicted. This review is ongoing. A new national protocol to ensure that all sudden infant deaths are investigated properly was announced in late 2004 following an inquiry chaired by Helena Kennedy QC.

Angela Cannings says: "We're still suffering the aftermath of this whole episode. This film is for Jade, my daughter's benefit, so when she is older she can see what it was all about.

"The general public would assume that we've got back together and that's it. But there is an awful lot of healing. It doesn't just heal overnight. Even now I sit and think why we had to go through all that.

"We've had quite a lot to do with the scriptwriter, the BBC has been very good. They've dealt with us very fairly."

Sarah Lancashire adds: "I'm delighted to be playing the part of Angela. When I read the script I was very moved. The loss of any child is a dreadful thing, the loss of three is unimaginable. Whilst any parent could relate to the anguish that Terry and Angela must have felt I cannot comprehend the strength it must have taken to sustain Angela through even a part of a life sentence. Theirs is a remarkable story."