External gates locked blocking escape route

[Guest Connor Fowle]

On site we have a locked gate that blocks the way out from a fire route, is the gate allowed to be locked and only opened by key when there is an evacuation in process. 

If not what solutions are there? 

[AnthonyB]

No, not if it traps people and stops them exiting a building - it needs to have an escape fastening not requiring a key from the inside - the Safelincs website has a variety of options for sale.