Not if they stuck to marching, no. If they turned violent, or deliberately intimidated people, then yes. Under UK law if they said certain things that are con

Not if they stuck to marching, no. If they turned violent, or deliberately intimidated people, then yes. Under UK law if they said certain things that are considered hate speech laws, then again yes. There are also laws around protests (where and when, legal mechanisms of bans, orders banning particular individuals from particular actions) so if anyone breached those, again, yes.