Portugal’s Socialist government will introduce a sugar tax on soft drinks in 2017 which is expected to raise €80m (£72m) for the public health service, a budget bill presented on Friday showed.

The announcement comes just three days after the World Health Organisation urged countries to start taxing sugary drinks, pointing to evidence that price rises can dramatically reduce consumption.

Under Portugal’s plans, drinks with more than 80 grammes of sugar per litre will be taxed at €16.46 per 100 litres.

Drinks with fewer than 80 grammes will pay a tax of €8.22 per 100 litres.

The tax would raise the price of a standard 330-millilitre can of Coca-Cola, which contains 35 grammes of sugar, by 5.5 euro cents.

The new tax would apply only to soft drinks. Sugary drinks based on milk or fruit juice would be spared.

The previous centre-right government, in power until November 2015, considered introducing a sugar tax on drinks and foods that contained too much sugar or salt, but dropped the idea.

Only a handful of other countries, such as France, Mexico and South Africa, have introduced a sugar tax.

The British prime minister, Theresa May, in August released proposals for such a tax as part of her Conservative government’s strategy to combat childhood obesity.

The Socialists came to power in Portugal last year after they teamed up with the Communists and the far-left Left Block to oust the centre-right administration.

The small leftist parties did not formally join the new government, but the prime minister, Antonio Costa, relies on them for a majority in parliament to pass legislation – an unprecedented political arrangement in 40 years of Portuguese democracy.