The idea
There should be a legal standard set for the use of Free Speech, which in my view should allow all speech (typed or written) except that which is an incitement to violence or a treasonable offence.
In the case of speech which is clearly an unsupported misrepresentation, whether of individuals or groups of persons, this should be a matter for civil redress, not the criminal justice system.
This piece of legislation should be constitutionally safeguarded, superseding all other legislation, past or future, and could only be repealed by a specific further Act of Parliament, thereby ensuring public debate.
Why is it important?
Starting with an outlawing of speech that is deemed "racist", under a Public Order Act, this principle that the State has the right to say what speech is legal and what is illegal has spread to Religious groupings (the Racial and Religious Hatred Act 2006), and homosexual persons (by an extension of the protection in the Public Order Act).
This has seen people being arrested, where no other crime had been committed, nor an incitement made to commit any other crime.
The dangerous precedents that have been set are seeing further infringement on the right to speak without fear, as this week the Scottish Parliament has outlawed "abusive" language in public and in private.
Unless there is a particular constitutional safeguard enshrined in law, speech could be further narrowed into the confines of the particular prevalent ideology of the day.