A judge at an administrative law court in Madrid has banned an event that was to be held on Sunday, September 17 in support of the independence referendum in Catalonia.

The event was to have taken place in a municipal building, which is why the Popular Party in Madrid City Hall could petition the administrative law judge for the event's prohibition.

The judge said the event clearly supported an act—the Catalan independence referendum—which had been suspended, which was unconstitutional, and which had not been authorised by the central government.

"It is not possible for an event that is openly against the Constitution and the resolutions of the Constitutional Court to be helped by a municipality that, as has been expressed, also has a duty to uphold the law."

"In no way", said the judge, can the use of city facilities to promote an illegal and unconstitutional act be considered to be in the general interest.

A City Hall district had authorised the use of the Matadero public event space in the Spanish capital for the gathering, titled "Madrid supports the right to decide", on September 6.

Parties may not appeal this ban but the court will hear a response from Madrid City Hall within three days.

The organising group, Madrileños por el Derecho a Decidir ("Madrid residents who support the right to decide"), said on Facebook that it would go ahead with an expression of support for the Catalan referendum on Sunday anyway: "faced with threats against the freedom of assembly and speech".

José Luis Martínez-Almeida Navasqüés, the Popular Party spokesman at Madrid City Hall, said "in the end, a judge had to tell [Madrid Mayor] Carmena to stop the event".

"There is no room for separatism in Madrid. Here we respect the Constitution, the law and the rule of law."

"We ask Carmena to obey this sentence."