Protesters took to the streets of cities across Spain over the weekend, with one of the biggest gatherings being in the northeastern city of Barcelona, to demand a reduction in the country's housing rental prices.

The cost and scarcity of affordable rental properties is becoming an increasingly big issue, and inspired around 22,000 people to take to the streets of Barcelona on Saturday.

According to a study by the Bank of Spain, Spaniards face some of the highest rent and utility bills anywhere in the European Union, with nearly 40 percent of renters spending an average of 40 percent of their income on those expenses, as opposed to an EU average of 27 percent.

In addition to the size of the bills, there is also a very limited supply of rentable properties. In the 38 member countries of the Organisation for Economic Co-operation and Development, the average percentage of housing available for rent is 7 percent. In the Netherlands it is 34 percent, in France it is 14 percent but in Spain, it is just under 2 percent.

Short-term renters, particularly tourists, add to availability problems, and Ignasi Marti, a professor from the Dignified Housing Observatory at the Esade business school in Barcelona, told the Euronews website: "We are talking about a housing emergency. It means people having many difficulties both in accessing and staying in their homes."

Tourism accounts for 15 percent of Barcelona's income, and currently the city has 10,000 apartments licensed for short-term rental.

But last month, local authorities announced that they would not renew any tourist apartment licenses after they expire in 2028, to try and free up places for locals.

One of the organizers of Saturday's Barcelona protest was the city's Tenants Union, and a group spokesperson, Carme Arcarazo, said if something was not done soon to alleviate the situation, it may be time for a rent strike.

"I think we, the tenants, have understood that this depends on us. That we can't keep asking and making demands to the authorities and waiting for an answer. We must take the reins of the situation," she said. "So, if (property owners) won't lower the rent, then we will force them to do it."

The latest wave of protests, which included smaller gatherings in the northern town of Burgos, and Jerez de la Frontera in the south, comes in the wake of a similarly-themed demonstration in Madrid, which prompted Prime Minister Pedro Sanchez to call a housing summit to discuss the issue.

But the event included input from real estate developers, and Associated Press reported that the Barcelona's Tenants Union boycotted it, likening it to inviting tobacco companies to a summit on how to cure cancer.