“It is not justifiable to have to pay for this (water), which doesn’t cost anything for these establishments,” cantonal MP Romain de Sainte Marie told the Tribune de Genève newspaper.
At the moment no law exists and each restaurant does as it wants, with some charging for tap water and others not, the Socialist party MP noted.
“Charging for water encourages customers to order a sweet or alcoholic drink”, rather than water, which is more healthy, he said.
De Sainte Marie is proposing legislation for the Geneva parliament to consider.
But the Geneva association of cafe and restaurant owners is opposed to such regulation.
Even if only a minority of restaurants charge for tap water, they should have the freedom to make this decision, the association maintains.
“This project is ridiculous,” the association’s president Laurent Terlinchamp told the Tribune de Genève.
“The MP did not even consult with us.”
Terlingchamp said the practice of charging for tap water is not widespread.
“It’s sad that certain (restaurants) are obliged to sell water to make ends meet but they rest a minority.”
The Tribune quotes the owner of a Geneva pizzeria as saying his restaurant depends on drinks for 75 percent of its turnover.
The restaurant charges 2.50 francs ($2.66) per person for a pitcher of tap water, with an exception made for students.
“We will respect the law if it comes into force but we will be losers,” the pizzeria owner is quoted as saying.
Customers who want tap water usually have to specify this in Geneva restaurants or they face getting served bottled mineral water.
Ironically, the canton’s utility company SIG boasts that tests show its tap water, largely sourced from Lake Geneva, is of better quality than bottled water.