Mr. McCartney expressed solidarity as he spoke at a rally held to coincide with similar rallies in Belfast and Dublin, to show support with the people of Catalan following their historic declaration of independence this week.
He said “The democratically elected Parliament of Catalonia this week made a declaration of Independence. It is a historic step towards Catalan statehood.
“The right to self-determination is a corner stone of international law and this declaration must be respected.
“We want to express our solidarity with the people of Catalonia from the people of Derry on this historic week.”