i work in a bakery of which i have to use an office as part of my job, there are 3 offices which are joined by a single door, if a fire was to start blocking my office door this would leave me with no way to get out as the other office doors are locked which if left open could lead me to a point of escape but this is being blocked leaving me vunreble , can this doors be allowed to be locked or are they meant to be open as part of an escape route.

I do not fully understand the layout of these offices but if you are concerned talk to your boss or you could go direct to the Fire and Rescue Service who are the enforcement authority who would conduct a fire risk audit to see if the fire risk assessment is suitable and sufficient.

Check out http://www.firesafe.org.uk/uk-fire-rescue-services-details/ for your local FRS.