Britain has joined nearly 200 countries in signing up to a United Nations resolution to eliminate plastic in the sea.

If current pollution rates continue, there will be more plastic in the sea than fish by 2050, said the United Nations Environment Programme (UNEP) which organised the meeting.

Eight million tonnes of plastic - bottles, packaging and other waste - are dumped into the ocean every year, killing marine life and entering the human food chain. WWF said the world was currently in the grip of a 'global crisis'.

Under the resolution, which was signed by all 193 members of the UN. countries agreed to start monitoring the amount of plastic they put into the ocean and to explore ways to make it illegal to dump waste in the seas.

Britain has already taken some steps to cut down on plastic waste, including the 5p plastic bag charge and a recent ban on microbeads. Michael Gove, the Environment Secretary, is also currently considering bringing back bottle banks to encourage people to recycle their plastic bottles.

Theresa May also hinted this week that foreign aid funding will be diverted to help tackle the plastic pollution crisis.