Spain's Queen Sofia on Wednesday cancelled the trip to London she had planned for later this week for Queen Elizabeth II's Diamond Jubilee because the Spanish government feels that it would be "unsuitable" after the fishing conflict with Gibraltar and the announced visit to The Rock by Britain's Prince Edward.

The queen's attendance at a luncheon scheduled within the framework of celebrations surrounding the 60th anniversary of Elizabeth II's ascent to the British throne was cancelled because "under the current circumstances" the Spanish government feels that it would be "unsuitable" for her to participate in the event, spokesmen for the Royal Palace said.

The same sources said that the Royal Palace informed the British Royal Palace on Wednesday afternoon that Queen Sofia will not attend the Friday luncheon offered by Elizabeth and her husband, Prince Philip, the Duke of Edinburgh, at Windsor Castle, without specifying the reasons for her absence.

Diplomatic officials told Efe that the conflict that arose after the breakdown in negotiations on Tuesday between Spanish fishermen and the government of Gibraltar to try and resolve the fishing blockade in the Bay of Algeciras was the impetus that motivated the Spanish government to advise the Royal Palace of the cancellation of the trip.

The conflict comes after the scheduling of the June 11-13 visit to The Rock by Elizabeth's youngest son and her husband.

In addition, there is a third difficulty: namely, at the events commemorating Elizabeth's 60th anniversary on the British throne the band from the British Gibraltar regiment has been scheduled to play.

Thirty-one years ago, the controversy over sovereignty of Gibraltar led the Spanish monarchs to cancel their attendance at the wedding of Britain's heir to the throne, Prince Charles, and Lady Diana.

In 1981, Charles and Diana's decision to make a stop in Gibraltar during their honeymoon on the yacht Britannia led the Spanish king and queen to decline the invitation to the wedding.

Since that time, various members of the British royal family have visited the colony on Spain's southern coast and sparked protests by the Spanish government.

The latest royal visit to The Rock was by Princess Anne, Edward's sister, in 2009 to inaugurate a military medical center.

Then, the visit was characterized by the Spanish Foreign Ministry as "untimely" and Minister Miguel Angel Moratinos communicated to his British counterpart, David Miliband, "the rejection, consternation and indignation of the (Spanish) government."

Prince Edward visited Gibraltar in 2001 to present several Duke of Edinburgh's Awards to young Gibraltar residents.

On that occasion, Spanish Foreign Minister Josep Pique told the British Embassy in Madrid of Spain's "displeasure" and "discomfort" regarding the visit. No official protest was made, however, because - he said - the trip was not an official one and had no political content.

On May 8, the Spanish Foreign Ministry summoned British Ambassador Giles Paxman to communicate its "disgust and unease" over Prince Edward's visit to Gibraltar in June.