José María Aznar has resigned as honorary chairman of the Popular Party after 12 years, he announced in a letter posted on his website (pdf).

Writing to the Prime Minister, Mariano Rajoy—on a trip to New York today to chair a meeting of the UN Security Council—Mr. Aznar said: "I want to communicate to you, via these lines, my decision to resign as honorary chairman of the Popular Party", adding that PP members had "generously" reappointed him to the post five years ago during the 2012 party conference.

A Popular Party spokesman told The Spain Report there was as yet no official reaction to Mr. Aznar's resignation.

Aznar, who was Prime Minister of Spain from 1996-2004, and had previously been chairman of the Popular Party since 1990, said his resignation is related to the recent distancing of the party's now former think tank FAES (Foundation for Social Studies & Analysis), which he still chairs.

"Today the new situation of the Faes [sic] Foundation, which since its creation in Valladolid in 1989, when I was the First Minister of Castilla y León, has been linked to the Popular Party; its independence and, therefore, its unlinking from the Popular Party, make this decision, sincerely, advisable."

In October, the conservative think tank announced it was formally splitting from the Popular Party after a series of disagreements over policy and events.

Following the recent death of the former long-time PP Mayor of Valencia, Rita Barberá, in a hotel near Congress in Madrid, Mr. Aznar expressed his regrets at the way his party had treated her as judges investigated some aspects of her management as part of a corruption case: "I am sorry that Rita Barberá has died having been excluded from the party to which she dedicated her life".

Deputy PP regional affairs secretary Javier Arenas (Andalusia) said Mr. Aznar would always "hold a place of honour" in the party "and would still be our colleague". "He has been key in the history of the PP so that we could represent a majority of society", he said.

In his letter, Mr. Aznar announced that, for the first time, he would not now attend the upcoming party conference, scheduled for February 2017: "I have taken part in all of the Popular Party conferences since 1979".

He said he would stay on as an ordinary member of the PP and his only thanks were to grassroots party members for their "dedication, effort and service to Spain, and particularly, for their generosity and loyalty to me for so many years".

Mr. Aznar did not thank Mr. Rajoy in the letter, although did wish his successor well before signing off.