For Info, from MATS part 1 since last year:
Instructions to aircraft in the final stages of approaching to land
15.3.1 The final approach represents an increased period of flight deck workload. Unusual situations and emergencies during this period can be particularly demanding for the pilot. Therefore, with the exception of instructions to go-around, instructions shall not be issued to aircraft in the final stages of approaching to land that would require it to deviate from its expected flight path unless exceptional and overriding safety considerations apply.
So who judges whether it is an exceptional and overriding safety consideration??