While many Londoners cannot get enough of French food, culture and lifestyles, they will be less keen on pollution drifting across the Channel.
A leading environmental expert, Professor Frank Kelly, is warning that on some high pollution days in the capital, a considerable level of harmful particulates levels will have seeped into the South East from the Continent.
The King's College London academic estimates that between 3,000 to 5,000 people a year are dying early in the capital due to pollution - some having their life shortened by up to ten years.
Traffic pollution, particularly from diesel engines, is by far the biggest pollution killer in London, he says, with poor air from overseas adding to the public health impact when an easterly wind blows.
Failure to take decisive action to deal with such a big killer would normally spark uproar. But it's a silent scandal happening in our midst.