A blonde in a low-cut blue dress has stirred up the most deeply conservative sectors of Spanish society, kicking off a debate on the role of the monarchy and prompting allegations of sexism enshrined in the constitution. The blonde in question - Norwegian model Eva Sannum - is reported to have been dating the heir to the throne Prince Felipe for three or four years, giving rise to speculation that an engagement might be imminent. Sannum was photographed at the side of 32-year-old Felipe at the Norwegian royal wedding in Oslo in August and the question of whether she had been introduced to his mother Queen Sofia was on the lips of every gossip columnist. More revealing than Sannum's satin dress are the passions that the issue arouses in Spain in the aftermath of the controversial Norwegian royal wedding, when Crown Prince Haakon married a single mother with a wild past. Outrage has risen from the conservative depths of Spain's otherwise liberal society about the possible match between Felipe and Eva, reported to be 25. It would be inconceivable to see the throne occupied...by a young woman whose qualifications are her perfect vital statistics, wrote Carlos Seco Serrano in a column in the staunchly monarchist newspaper ABC. Younger Spaniards have expressed their concern in several on-line opinion polls showing more than 60 percent of respondents - typically under 25 years old - oppose the match. The majority of Spaniards from across the political spectrum respect Felipe's father, King Juan Carlos, for pushing the country towards democracy after the death of dictator Francisco Franco in 1975 and standing up to an attempted coup in 1981. But many consider themselves republicans, raising questions about the future of the monarchy under Felipe. Right-wing commentators have seized on reports that the potential bride is from a modest background, her parents are divorced, and she has at least once modelled underwear. Unfortunately for the prince, what others think is by no means irrelevant. Spain's constitution gives Felipe the right to the throne in preference to his elder sisters and states he must have clearance from the royal palace and parliament for his choice of wife. One would simply remind the Prince of Asturias that, in exchange for his countless privileges, he would be advised to exercise special caution and reflection in choosing his future wife, wrote columnist Alfonso Ussia, also in ABC.