Thousands of Britons with holiday homes in France and Spain could be prevented from renting out their properties to tourists if new laws come into effect.
It could also mean that holidaymakers end up paying more for accommodation as they won't be able to access cheaper rates by going direct to the owners.
Expatriates who rent out their homes while they are elsewhere will also be affected if the controversial laws are passed.
A crackdown on holiday rentals is expected to begin in Paris, Lyon and Marseille next week, with the rest of France likely to follow suit.
Meanwhile, licensing in Spain is thought to come into play during the springtime.
It is estimated that around one million properties in the country are owned by Brits, with some acting as the homes of expats and others purchased solely for holidays.
In the past it has been relatively easy to rent out such properties and worth doing even if expats are away for just a few weeks, but the new laws will require the owners to pay a fee to the local council to obtain a licence.
Strict conditions will also need to be adhered to, such as 24-hour contactability in case of emergencies, safety inspections and obtaining hygiene certificates.
In France, properties that are let out will be seen to have changed their use and come with a fee for making this official.
This could affect 20,000 Brits that have bought holiday homes in popular regions, such as Normandy and Brittany.
Around three-quarters of the overnight stays in Spain last year were in unregulated premises, according to La Caixa bank.
This is being seen as a lost opportunity by the country, which has been hit hard during the recession, as income from rentals is not necessarily being declared and therefore it is missing out on taxes.
Key figures in the hotel industry have also been lobbying the government to do something about the surge in rentals, as it is making a dent in their profits.