A mediation with the independence movement that the PP did accept
At the request of the then Spanish president, Arriola mediated to stop the 9-N consultation
Barcelona"What is happening now in Spain is the most serious thing that Spanish democracy has faced since 23-F [the February 23, 1981 coup attempt].” It was with these forceful words that PP leader Pablo Casado spoke today about the decision of the Pedro Sánchez government to accept the inclusion of a rapporteur in the inter-party talks on Catalonia. The PP leader ignored the fact that the government of Mariano Rajoy appointed a mediator —and not a rapporteur— before the consultation of November 9, 2014, with the aim of stopping the vote.
When on December 12, 2013, Catalan president Artur Mas announced that he had agreed with the rest of the pro-sovereignty parties on a date and a two-fold question for the consultation, the PP's go-to sociologist, Pedro Arriola, had been meeting for months in both Madrid and Barcelona with Joan Rigol, the historical leader of UDC [Unió Democràtica] and the chair of Catalonia’s National Pact for the Right to Decide, acting as the President Mas's emissary, as the newspaper El Periódico reported. They were conversations that all had agreed to deny if they were made public, and that were aimed at avoiding the head-on political collision.
A Spanish socialist, José Enrique Serrano, the former chief of staff of PM Felipe González and later José Luis Rodríguez Zapatero, joined the talks (specifically in January 2014) at the request of Alfredo Pérez Rubalcaba, then General Secretary of the Socialist Party. This strategy was blessed months later by the current Spanish president, Pedro Sánchez, who has always defended the path of dialogue for resolving conflicts that are acknowledged to be political. The three leaders held talks until just hours prior to November 9th, with several proposals on the table, such as a constitutional reform as a third path, the possibility of changing the consultation question, and even some formulas for seeking a constitutional justification for the [non-binding] vote.
Urkullu, the other mediator blessed by Rajoy
And that was not the only precedent. Three years later, with Rajoy still in La Moncloa and Carles Puigdemont in the Palau de la Generalitat, the two governments accepted the mediation of Basque president Iñigo Urkullu to try to prevent the Catalan Parliament from passing a unilateral declaration of independence (UDI) and the Spanish Senate from imposing direct rule on Catalonia. On October 3rd Urkullu offered himself to European Commission President Jean-Claude Juncker to promote a "European mediation", and noted that the EU "was not built by exchanging reproaches and underscoring the limits of the law, but by listening, understanding each other and building together".
Up until the last minute, the Basque president took advantage of his good connections with Madrid and Barcelona to try to stop the UDI and direct rule, via meetings, calls, messages, and emails. In the writings, collected in Supreme Court briefs, Urkullu insisted on the elections, always from the premise that, as a nationalist, he understood the arguments of the Catalan president. Urkullu had already reached an agreement with Puigdemont, a couple of days before the UDI, but the refusal of the Spanish government to not apply direct rule unless the UDI was dropped led to the failure of the mediation, much to the despair of the Basque leader.