PARIS (AFP) - Air-conditioned shops in France will be ordered to keep their doors closed or risk being fined, a minister said on Sunday (July 24) while announcing an upcoming rule to combat energy wastage.

Leaving the doors open when the air-conditioning is on leads to "20 per cent more consumption and... it's absurd", French Minister of Ecological Transition Agnes Pannier-Runacher told RMC radio.

The minister said there are also plans to restrict the use of illuminated signs.

"In the coming days, I will issue two decrees: the first will widen the ban on illuminated advertising, whatever the size of the city, between 1am and 6am", with the exception of airports and stations, Pannier-Runacher told the Journal du Dimanche newspaper.

"The second will ban shops from having their doors open while the air-conditioning and heating are working".

Some cities in France - which like other parts of Europe has been gripped by a heatwave recently - passed municipal by-laws in July, imposing fines for offending air-conditioned shops.

The government now plans to extend this to the whole country, with a fine of up to €750 euros (S$1060) - but will emphasise the education of shopkeepers in the first instance.