Theresa May hopes to use the announcement to encourage the Commonwealth heads of government to join the fight as the meeting opens formally on Thursday. “The Commonwealth is a unique organisation with a huge diversity of wildlife, and environments – so it is vital we act now,” the prime minister will say, urging all Commonwealth countries to participate.

Cotton buds, often flushed down the lavatory, are one of the most serious sources of marine pollution. They are small enough to be eaten by birds and marine life. Altogether it is estimated that there are 150m tonnes of plastic in the world’s oceans, and over 100,000 sea mammals die from eating or getting tangled up in plastic waste.

Plastic microbeads have already been banned, and the introduction of the 5p plastic bag charge in England has led to a dramatic fall in their use: 9bn fewer bags have been distributed, Department for Environment, Food and Rural Affairs (Defra) figures show.

Michael Gove, the Defra secretary, called single-use plastics a scourge. “It is only through government, business and the public working together and the public working together that we will protect our environment for the next generation,” he said. A consultation will start later in 2018, and a ban could be enforced as early as next year.

Scotland has a head start on England: the Scottish government announced a consultation on plans to ban the manufacture and sale of plastic-stemmed cotton buds in January. Campaigners said it would cut the country’s marine plastic pollution by half.

Other work, such as the Treasury’s research into the impact of a levy on disposable coffee cups and a deposit return scheme on plastic bottles, is also under way in a bid to wean Britons off their polluting habits.

But sources say behaviour will not be changed through regulation and compulsion. Ministers are keen that the public should be better informed about plastics that are reusable and recyclable, and want the process to be incremental and well supported, as the plastics bag levy was when it was finally introduced.

A further incentive to avoid the use of plastics is the impact that reduced demand for the oil-based material would have on the fossil fuel industry. BP announced recently that it would “dent” demand.

There is evidence that increasingly prosperous countries of the global south are beginning to react to environmental damage and pollution. Earlier this year, China cracked down on imports of plastic rubbish, revealing how much the UK relied on sending its waste offshore.

In India, Delhi banned all forms of disposable plastic more than a year ago after complaints about the illegal mass burning of plastic and other waste at local rubbish dumps, and the air pollution it caused. The sites were supposed to operate as waste-to-energy plants.

The evidence of the damage that plastics do not just to wildlife and the food chain but to some of the world’s most beautiful places is now widely reported. The government has committed £61.4m to its latest initiative, some of which will be used for research and to help Commonwealth countries develop ways of stopping plastic waste entering oceans.

Read more at the Guardian website

Photograph: Emma Innocenti/Getty Images