A lunch for sovereigns from around the world celebrating the diamond jubilee of Britain’s Queen Elizabeth II was marked Thursday by a withdrawal, protests and controversy over the guest list. Spain’s Queen Sophia has pulled out of Friday’s glittering event at Windsor Castle, west of London, amid tensions over Gibraltar, while there were protests over the reported attendance of Swaziland’s King Mswati III. Bahrain officials also said King Hamad, whose Gulf island country is in a state of civil unrest following a deadly crackdown on protests last year, should be attending, angering rights groups. Buckingham Palace will neither confirm who is on the guest list nor comment on the lunch, being held to mark Queen Elizabeth’s 60 years on the British throne. Queen Sofia cancelled her trip due to tensions with Britain over the tiny Gibraltar peninsula, which Spain ceded to Britain in perpetuity in 1713. “The government considers it is hardly adequate that in the current circumstances, Queen Sofia take part in Queen Elizabeth’s jubilee,” a spokesman for the Spanish royal household said Wednesday. Last week Madrid protested to London over a planned visit to Gibraltar by Queen Elizabeth’s youngest son Prince Edward and his wife Sophie, Countess of Wessex. Edward’s June 11-13 trip is part of celebrations to mark the jubilee, with all Commonwealth realms and some British overseas territories getting a royal visit on the queen’s behalf. Spain’s King Juan Carlos was due to attend the Windsor lunch with his wife, but after he underwent hip replacement surgery last month following a fall during an elephant hunting expedition in Africa, the royal palace announced only the queen would attend. Prince Charles, the heir to the British throne, and his wife Camilla, the Duchess of Cornwall, are hosting a dinner for foreign sovereign monarchs at Buckingham Palace in London on Friday evening.