An Enfield woman rented out her flat on Airbnb illegally has lost a court case which could affect millions of leaseholders.

Iveta Nemcova's neighbours were concerned about strangers regularly staying in her one bedroom, first floor flat, and asked the block's freeholder to take action.

In the country's highest property court, the Upper Tribunal's Land Division, Ms Nemcova, an interior designer originally from Slovakia, admitted renting out her flat, but said her lease did not stop people staying there while she was away, and that she lived in the flat for four days a week on average.

However presiding Judge Stuart Bridge disagreed, with the court deciding homeowners whose leases state their properties can be used “as a private residence only” cannot rent out their homes short term, depending on the conditions of their lease.

The private residence clause is a common feature of leases, with around four million people living under them in the UK.

Judge Bridge said: “In order for a property to be used as the occupier's private residence, there must be a degree of permanence going beyond being there for a weekend or a few nights in the week”.

The decision means thousands of prospective hosts on Airbnb, TripAdvisor and other sites – with the two mentioned being used by Ms Nemcova – could be renting out their homes illegally.

A spokesman for Airbnb said: “We remind all hosts to check and follow local rules before they list their space. This is also made clear on our responsible hosting page, which contains useful information and resources on the rules for home sharing.”