@Region Philbis,
It sets a precedent, parliament can order the decapitation of the head of state.
Trump likes to style himself king so you have a chance to join us and the French in making America anti monarchist again.
Having said that Cromwell's skull had a long journey, exhumed, put on a spike and passed from one collector to another until being finally laid to rest in 1960.
Charles II went after all those who signed his father's death warrant with a vengeance.