Addy puts forward the case for the UK to follow the US in how producers choose scripts. At the moment in Britain you get work by writing an original spec which doesn't really prove you can write other people's characters.
The counter-argument from producers has been that they want to see the writer's own voice. However, the writers with original voices stand out on continuing drama on the BBC as they do on HBO or Channel 7. Why wouldn't they stand-out in spec scripts?
Stewie is a member of a writers group whch gives him a writing assignment each month. For March he had to "write a spec episode of a current UK TV series.". On the surface it might seem a complete waste of time but just as in the States producers now want to see original pilot specs in portfolios, there are producers over here who now want to see a spec of an existing show - even their own show.
But even if I were to reveal who those producers/shows were, it's actually a brilliant writing exercise in its own right which not only gives us an insight into what the process is all about but by 'shadowing' an existing show we are also learning how to create our own.
Although, there are some gorgeous drama press packs out there (take a bow ITV for taking my stroppy email to heart.) I would recommend not using them and creating a bible from the show itself - from what the characters actually say and do. There's other things to bear in mind such as the locations used and the structure of each episode in terms of A, B and C storylines.