“Suddenly applying a cork stopper to tourist lets in an area, announcing that in advance, is simply going to lead to what is happening in Lisbon," said the mayor, Rui Moreira, in a reference to a last-minute rush in recent days to register such properties in Lisbon before new rules take effect. "We won’t do that."

New legislation enabling city councils to restrict tourist lets recently came into effect, as a measure to make housing and rental prices more affordable for residents, with Lisbon already having pledged to act soon.

House prices and rents have been rising steeply in recent months, particularly in Lisbon and Porto, in part because of strong demand from foreign buyers and properties being withdrawn from the long-term rental market to be used for more lucrative tourist lets.

“From what I understand we have to be able to measure short-term rentals in a way that these are accompanied by investment in rehabilitation for housing,” Moreira said.

Moreira added that an alternative solution would be proposed by Porto to avoid “killing the goose that laid the golden egg” of tourism.

Lisbon's city council has already unveiled plans to suspend new registrations for short-term rentals in some of the city's older neighbourhoods of Madragoa, Castelo, Alfama, Mouraria and Bairro Alto.

Portugal’s Socialist government has been working on a set of new measures aimed at increasing the number of homes available at affordable prices, to be included in the 2019 state budget.