Fascinating mix of Religious news outlets and Socialist ones reporting on yesterday...nobody else.
Cops in the UK have a long tradition of suppressing protest, whether or not the protest is legal or harmless. This is its own justification, to them, and the government generally supports them in it regardless of which party forms that government.
If you haven't lived in the UK, you may not be aware of how awful the Right-wing newspapers here are, or how powerful. They are absolutely capable of bringing down governments and they know it. This means that the government usually has to do whatever they want - again, regardless of party - without any regard for legality or effectiveness. One of the things the Right-wing newspapers loathe the most is visible public dissent, especially environmentalist dissent. When environmentalists dare to exist publicly, the newspapers will demand that they're beaten into compliance, and the cops are usually happy to oblige.
This is why groups like XR and JSO have a long record of having their events shut down by the cops, then suing the cops, and winning in court. The events themselves were never illegal, but that also wasn't a relevant factor in the events being shut down. Cops aren't there to enforce the law.