Not many couples can boast of having the prime ministers of Britain and Italy as guests at their wedding, but Spanish Prime Minister Jose Maria Aznar's daughter and her fiance are expected to have that honour. Sources in Aznar's Popular Party say Tony Blair and Silvio Berlusconi will be on the guest list for Spain's wedding of the year on Thursday, although Blair's presence has not yet been confirmed by his Downing Street office. Some news reports say the two politicians will be witnesses at the wedding of 20-year-old Ana Aznar, the most eligible young woman on Spain's political scene, and 31-year-old Alejandro Agag, a former rising star in the centre-right Popular Party. Berlusconi told reporters in July he had bought a new suit for the wedding but would have to go on a diet to fit into it. Aznar stayed away from the United Nations Earth Summit in Johannesburg because it took place so close to the wedding. If in days of old a royal marriage could secure strategic interests, this wedding seems to reinforce a budding alliance between three free-market leaders - Aznar, Blair and Berlusconi - that has become a growing force in the European Union. Everyone who is anyone on the Madrid political and social scenes will be among the 1'000 guests at the wedding between the slight, dark-haired Ana Aznar and bespectacled and serious-looking Agag. Agag has been a personal assistant to Aznar, a member of the European Parliament and secretary general of the European People's Party. But he has set his political career to one side, at least temporarily, to become a director of a Portuguese bank. Ana, who spent the summer with her parents in Minorca, will continue with her studies after the wedding. Ana, said to take little interest in politics, is the middle child of Aznar and his wife Ana Botella, who also have two sons. After leading the Popular Party to two election victories, Jose Maria Aznar enjoys great prestige. He has said he will not seek a third term in 2004 and senior party figures are competing to be anointed as his successor. The wedding, presided over by Archbishop of Madrid Antonio Maria Rouco Varela, will be held at the imposing 16th century monastery built by Philip II at El Escorial, near Madrid. Crooner Julio Iglesias is reported to have postponed a concert to attend the wedding, and opera singer Placido Domingo is also rumoured to be on the guest list. Details of the ceremony, and the reception, said to cost as much as 120'000 euros ($119'000), have been filling the gossip pages for weeks.