Spain's Deputy of Public Prosecutions, José Manuel Maza, signed an order to provincial prosecutors in Barcelona, Tarragona, Lérida and Gerona on Wednesday, instructing them to investigate 712 Catalan mayors for allowing the use of municipal facilities for the independence vote on October 1.

Maza also named the Catalan police, the Mossos—specifically—as the force that would act as judicial police to arrest the mayors "in the shortest period of time possible" if they did not comply with the prosecutor's investigation.

The mayors will be investigated "in relation to alleged acts of cooperation in the organisation of the illegal referendum".

The list of 712 towns the prosecutor's office is using as a reference is one produced by the Association of Towns for Independence (AMI), beginning with Aiguamúrcia, in the province of Tarragona, and ending 15 pages later with Vilanova del Vallès, in the province of Barcelona.

The mayors were warned, said the prosecutor's office, of their duty to stop the vote from being organised by the Constitutional Court on September 7, as well as the possible criminal consequences of not complying with the court's order.

The prosecutor's office also noted the Catalan government had asked the mayors to be able to use municipal facilities for the vote.

Given the long list of towns, Maza ordered prosecutors to being with the most populated ones first.