[Magic]

A codified constitution is basically a document with all of the main laws and rights in. It is soveriegn - and can't be stopped.

The UK is one of the last few countries NOT to have a codified constitution

Advantages
Setting it up would educate the puplic.
They are hard to ammend - this means it would be hard for a dictator to take total control. (Courts have the last say, not politicians)
It would clean up the UK laws - at the moment 100's of laws still 'exist' but are not enforced.
It would be a good way to modernise the UK's political system; eg House of Lords, Devolved Bodies (Scottish Parliament etc.)
Everyone would know there rights - it would be accesible. The Americans nearly know theres off by heart.
It cant be suspended, unlike the Human Rights Act

Disadvantages
It it hard to change - for example we made need to introduce a new law quickly, e.g terrorism. It can also get stuck in the past.
It can fix things for ever - it wouldn't allow for 'organic' change. Eg we may be stuck in Europe.
We have lasted for 100's of years in a developed society without one; why bother?
Our system allows for the government to get on with its job.
Judges would have the last say on how it is enforced - they are NOT elected. (We may have a power freak in control of it)