The Spanish government and the King of Spain were shouted down ("Out!") and whistled out when they arrived to stand at the head of the anti-terrorism march in Barcelona on Saturday, organised, in theory, in memory of the victims of the recent jihadi attacks in Catalonia and as a "unitary" stand against murderous evil.

While aerial footage of the long tail of what local police estimated to be some 500,000 marchers showed few flags, the area behind the authorities—the area that received the most television attention—was a sea of Catalan separatist ensigns.

And while the main front banner read "I'm not afraid", a secondary protest sign was visible almost right behind the King. His Majesty's face was on it, along with the message "your policies, our dead". In another area of the march, a giant rectangular banner—showing King Felipe shaking hands with the King of Saudi Arabia—was held aloft.

Today was not the day for such antics, 6 p.m. not the moment for vengeful, partisan bickering. It would solve nothing before 7 p.m. on a warm, sunny evening in the Catalan capital, but several thousand independence supporters could not resist everything being about secession from Spain anyway, even for a single hour, even as the relatives of the dead and injured only begin their process of grieving.

Instead of the march being wholly about remembering and supporting the victims and standing firmly against the jihadi terrorism that has just struck Spain, secessionists selfishly brought the focus onto them and their need to vociferate once again against all things Spanish.

If, as was entirely predictable, they were never going to be comfortable with the presence of ministers from Madrid, the Speakers of both houses of parliament or the head of state himself, there are any number of other acceptable identities that would have allowed for 60 minutes of shared contemplation of the horrors of Islamic State terror and a common desire for peace. "Europeans", "democrats" and "human beings" spring to mind without too much reflective effort.

Perhaps it is true that Catalan separatists are not afraid of jihadis with knives and vans wreaking sudden death and destruction among tourists and residents on the streets of Barcelona, as the slogan says, but they should be ashamed of their indecent behaviour in that city today.

If only for the sake of the victims and out of respect for their families.