Criminal Damage Act 1971 - damage caused by protesters and the defence of lawful excuse

The Criminal Damage Act 1971 was enacted to 'revise the law of England and Wales as to offences of damage to property ...'  First, a bit of history ...

History:

The Act was the product of the Law Commission's work (Report 29 published 23 July 1970) which, at the time, was part of a process of revising the criminal law with a view ultimately to codification. The latter has not been achieved. A link to the Commission's report is below.

The House of Lords Second Reading on the Criminal Damage Bill is worth reading for the succinct speech of Lord Hailsham (then Lord Chancellor), setting out the purpose of the Bill - Criminal Damage Bill Hl - Hansard - UK Parliament. 

The Law Commission reported

Post Office (Horizon System) Offences Bill

Today (13 March), the government introduced the Bill to - 'Provide for the quashing of convictions in England and Wales for certain offences alleged to have been committed while the Horizon system was in use by the Post Office; to make provision about the deletion of cautions given in England and Wales for such offences; and for connected purposes.'

Post Office (Horizon System) Offences Bill - Parliamentary Bills - UK Parliament

Explanatory Notes (pdf) - Post Office (Horizon System) Offences (parliament.uk)

Previous post 23 February - Law and Lawyers: Post Office ~ Horizon ~ proposed legislation (obiterj.blogspot.com)

Ministers introduce bill to quash convictions of Horizon scandal victims | Post Office Horizon scandal | The Guardian