A Dutch smoking ban will come into force in July next year for all restaurants and cafes -- including coffee shops where cannabis is the top attraction, the government decided on Friday.

"Coffee shops will be treated in the same manner as other catering businesses. They will be smoke-free," Prime Minister Jan Peter Balkenende told NOS television.

"It would have been wrong to move towards a smoke-free catering industry and then make an exception for coffee shops. People would not have understood that."

Establishments will not in fact have to be completely smoke-free. Proprietors will be allowed to set up a separate room or glass partition behind which people can smoke, but customers will not be served there to protect staff.

"Employees should not have to work in an environment were they are constantly exposed to the harmful effects of smoking," Balkenende said after the cabinet's decision on Friday.

Amsterdam's renowned coffee shops, where marijuana can be smoked openly in a relaxed atmosphere, are one of the city's big draws for tourists.

Coffee shop owners argue that the ban only applies to tobacco and was unlikely to hit them hard.

Whilst commonly mixed with tobacco, marijuana can also be smoked on its own, especially in pipes, vaporisers and other contraptions.

Soft drugs are officially banned in the Netherlands but under a policy of tolerance, buyers are allowed to have less than 5 grams of cannabis in their possession.