I do not often use this column to talk about individual constituents, especially those who are no longer constituents, but Hannah Deacon was in many ways exceptional.

For many years, Hannah and her family lived in Kenilworth and she came to see me about her son Alfie.

Alfie was suffering from a rare form of epilepsy, and suffering really is the right word. There were multiple seizures every week and frequent hospitalisation.

It was more than any little boy, and any family, should be expected to bear, but Hannah did not just bring me their problem – she had identified a solution.

She had already done a huge amount of research to establish that Alfie could be helped by cannabis-based medication, available on prescription in other countries but not in the UK.

Hannah was determined to change that, for Alfie and for others in his position.

That would mean changing the law. 

Now I know a little about what it takes to change the law, and I know how difficult it is to do. It requires patience, determination and both strategic and tactical acuity.

Luckily, Hannah had all those qualities in abundance.

It is difficult to make any change, but to make this change was even harder because the word 'cannabis' set off alarm bells in government and in the medical profession.

Both had to be persuaded that making cannabis-based medication available on prescription is a very different thing to making cannabis available on the street for recreational use – there are many drugs available with a prescription which have versions controlled by the criminal law without one.

Hannah persuaded me of that and persuaded other legislators too.

She then set about persuading the Home Secretary and she succeeded.

The Home Secretary at the time, Sajid Javid, was persuaded that he should change the rules so that cannabis-based medication should be available on NHS prescription to patients like Alfie, and Alfie was the first to benefit from an NHS prescription for the drugs he so desperately needed, and which changed his life.

It was a privilege to help Hannah in that effort and many others, including Alfie's GP, deserve considerable credit, but it was Hannah herself who remained the driving force behind this campaign throughout.

I marvelled at her capacity to fight this fight at the same time as caring for a desperately ill son.

She saved him and she was in the process of saving others in a similar position when she died, aged just 45.

It is a terrible loss for her family, who fought this fight with her, and for the many who continue to need this medication, for whom she continued to fight until she ran out of time.