Date:
Premises in the Standard Tier (capacity between 100-799)  will be required to take steps to ensure preparedness for, and protection from, terrorist attacks.
Martyn’s Law will improve protective security and organisational preparedness across the UK by mandating, for the first time, those responsible for certain premises and events to consider the terrorist risk and how they would respond to an attack.
Martyn's Law has recently completed pre-legislative scrutiny via the Home Affairs Select Committee and is awaiting introduction to Parliament – the draft provisions in the Bill are not yet law and will change. 
Premises and events in the Enhanced Tier will be required to take steps to ensure preparedness for, and protection from, terrorist attacks. The Enhanced Tier will apply to public premises and events (that have express permission to enter) with a maximum capacity of 800+ persons.