Theresa May will this week urge Commonwealth leaders to join together to tackle the scourge of discarded plastic in the world’s oceans, as she announces £60 million-worth of funding to develop new ways to address the problem.

The Prime Minister will warn that the threat to oceans is “one of the most significant environmental challenges facing the world today” and state that the Commonwealth is “uniquely placed” to build on the UK’s “transformative action”.

She will urge dozens of leaders at this week’s Commonwealth Heads of Government Meeting in London to join a newly formed Commonwealth Clean Oceans Alliance.

Each of the countries will be asked to pledge action on plastic waste, from banning microbeads to committing to cutting down on single-use plastic bags.

The Government announces a new £61.4 million tranche of funding, which will include £20 million to help prevent plastic and other environmental pollution in developing countries.