On the walls of the grand old houses of this Balearic port which attracts millions of foreigners every year, a new kind of graffiti has flourished: "Tourists go home".

Although still a minority protest, it points to tensions in Palma de Mallorca and elsewhere in Spain over rising numbers of visitors who are propelling the economy but also disrupting the lives of locals and straining services from transport to water.

With tourism accounting for 12 percent of economic output and 16 percent of jobs, Spain can ill afford a backlash.