If what has been said - that the Police can cause 3 aircraft to go around and Radar to break off approaches to another two aircraft, then things need to change. The Police seem to believe that they can disrupt anything they want at any time. Close motorways, effectively close LHR, (at least for a while) etc.
Someone with guts needs to sit down with the Police and get the situation at Heathrow changed. If the Police behave arrogantly and refuse to change, then that person with guts should go higher. Causing go-arounds from 600 ft is absolutely stupid.