Holiday rental properties available to tourists in the Majorcan capital of Palma generate more income for their owners than any other Spanish city, a new study has revealed. Rent Economics indicates an average gross income of €48,100 per annum (£41,162).

Only the Catalan capital of Barcelona comes close, with €47,000 per year (£40,221), while Ibiza, with €41,500 (£35,500), came third. The study, from analysts AirDNA, places the popular tourist seaside city as number one, despite demand being highly seasonal, like its neighbour, Ibiza. The high rates paid during the main summer season more than compensate for the drop in tourist activity in the low season.

Ibiza claimed the top spot for having the most expensive average price per day, at an annual average of €276.11 (£236.29). Palma, meanwhile, was €229.36 (£196.28).

The figures are drawn from Airbnb listings and do not take account of whether the lets are legal or not - apartment holiday lets in Palma are banned.

The researchers said these prices "rival or exceed many luxury hotel markets in Europe": "The power to set prices is greatest where tourism is most concentrated and property markets are tightest. For owners, the incentive to convert long-term leases into holiday rentals in these cities remains strong."

"In cities with peak demand in the summer, homes can remain empty for much of the year, underutilised by both tourists and residents," they added.

Occupancy data appears to support this trend. Palma came fourth with an average of 70%, behind Barcelona, Malaga and Madrid. Holiday rentals in Palma, like in Ibiza, "earn enormous income during short peak periods, but remain virtually empty during the off-season".

The study concluded that Spain is "at a crossroads" due to its dependence on its tourism sector and the researchers believe that data confirms that "regulation is no longer operational".

"Control measures must go beyond fines and establish real limits and incentives for alternatives to holiday rentals," they argued.

Palma, along with much of the rest of Spain, has been grappling with anti-tourism protests in the past couple of years. Just a few weeks ago, tourists in Majorca were reportedly surrounded and jeered by protestors as part the first coordinated effort by activists concerned by the effects of overtourism in southern Europe, including Spain, Italy and Portugal. In Palma, protestors held placards that included messages - many of which were written in English - such as "tourists go home" and "Mallorca is not your cash cow".

Meanwhile, in Barcelona, a group of tourists enjoying a drink were suddenly attacked by a woman armed with a plastic water gun, which now appears to be a protester's weapon of choice.